I-5: Aurora-Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062

Prepared for Oregon Department of Transportation

October 2020

Prepared by

I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062

Prepared for

Oregon Department of Transportation – Region 2 455 Airport Road SE Salem, OR 97301

Prepared by

Parametrix 700 NE Multnomah, Suite 1000 Portland, OR 97232-4110 T. 503.233.2400 T. 360.694.5020 F. 1.855.542.6353 www.parametrix.com

October 2020 │ 274-3012-031

CITATION

Parametrix. 2020. I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062. Prepared by Parametrix, Portland, OR. October 2020.

I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2

TABLE OF CONTENTS

EXECUTIVE SUMMARY ...... ES-1

1. IAMP AND PROJECT DESCRIPTION ...... 1-1 1.1 Background ...... 1-1 1.2 Study Area ...... 1-1 1.3 Purpose ...... 1-2 1.4 Problem Statement...... 1-3 1.5 Goals and Objectives ...... 1-4

2. EXISTING CONDITIONS AND INVENTORY ANALYSIS ...... 2-1 2.1 Introduction ...... 2-1 2.2 Land Use ...... 2-1 2.2.1 Existing Land Use and Zoning ...... 2-1 2.2.2 Growth and Demographics ...... 2-4 2.3 Transportation Facilities ...... 2-5 2.3.1 Road Facilities ...... 2-5 2.3.2 Pedestrian and Bicycle Facilities ...... 2-8 2.3.3 Public Transit Facilities ...... 2-8 2.4 Natural Resources ...... 2-8 2.4.1 Physical Setting ...... 2-8 2.4.2 Floodplains ...... 2-9 2.4.3 Surface Waters and Wetlands ...... 2-10 2.4.4 Biological Resources and Habitat ...... 2-12 2.4.5 Open Space and Parks ...... 2-14 2.5 Hazardous Materials ...... 2-14 2.5.1 Recommendations ...... 2-15 2.6 Cultural Resources ...... 2-16 2.6.1 Historic Resources ...... 2-16 2.6.2 Archaeological Resources ...... 2-17 2.6.3 Section (4f) and Section 6(f) ...... 2-18

3. TRAFFIC OPERATIONS – EXISTING AND FUTURE CONDITIONS ANALYSIS ...... 3-1 3.1 Traffic Analysis Methodology ...... 3-1 3.2 Existing Conditions...... 3-1 3.2.1 2018 (Existing) Traffic Volumes ...... 3-2 3.2.2 Intersection Traffic Operations...... 3-5 3.2.3 Freeway Ramp Merge/Diverge Operations ...... 3-6 3.2.4 Crash History and Trends ...... 3-6

October 2020 │ 274-3012-031 i I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 TABLE OF CONTENTS (CONTINUED) 3.2.5 Pedestrian and Bicycle Travel Conditions ...... 3-8 3.3 Future No-Build Conditions ...... 3-9 3.3.1 2042 Traffic Volumes ...... 3-9 3.3.2 Intersection Traffic Operations...... 3-9 3.3.3 Freeway Ramp Merge/Diverge Operations ...... 3-12 3.3.4 Safety ...... 3-13 3.3.5 Pedestrian and Bicycle Travel Conditions ...... 3-13

4. CONCEPT AND ALTERNATIVES DEVELOPMENT ...... 4-1 4.1 Process Overview...... 4-1 4.2 Concept Evaluation Framework ...... 4-3 4.2.1 Construction Cost ...... 4-3 4.2.2 Traffic Performance ...... 4-4 4.2.3 Right-of-Way Impacts ...... 4-4 4.2.4 Land Use and Business Impacts ...... 4-4 4.2.5 Specific Business and Farm Impacts ...... 4-4 4.3 Concept Screening ...... 4-5 4.3.1 TDI – Tight Diamond Interchange ...... 4-5 4.3.2 Central Roundabout Interchanges ...... 4-8 4.3.3 DIR – Diamond Interchange with Roundabout Ramp Terminals ...... 4-12 4.3.4 FDR – Folded Diamond Interchange with Roundabout Ramp Terminals ...... 4-15 4.3.5 FDS – Folded Diamond Interchange with Signalized Ramp Terminals ...... 4-18 4.3.6 DGR – Diamond Interchange with Gullwing West and Roundabout Ramp Terminals ...... 4-21 4.3.7 SPI – Single Point Interchange ...... 4-24 4.3.8 DDI – Diverging Diamond Interchange ...... 4-26 4.4 Selecting the Preferred Alternative ...... 4-29 4.4.1 Refinement of Alternatives ...... 4-29 4.4.2 Preferred Alternative ...... 4-34

5. PREFERRED ALTERNATIVE ...... 5-1 5.1 The Diverging Diamond Interchange ...... 5-2 5.2 Preferred Alternative Refinement ...... 5-4 5.2.1 Value Engineering (VE) Process ...... 5-4 5.3 Preferred Alternative ...... 5-4 5.3.1 Right-of-Way ...... 5-6 5.3.2 Transportation Performance ...... 5-7 5.3.3 Environmental Impacts ...... 5-7

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5.4 Phase 1 ...... 5-8 5.4.1 Right-of-Way ...... 5-9 5.4.2 Transportation Performance ...... 5-11 5.5 Access Management ...... 5-15 5.5.1 Preferred Alternative ...... 5-16 5.5.2 Phase 1 ...... 5-17 5.6 Land Use and IAMP Implementation ...... 5-18 5.6.1 Local Policy and Permitting ...... 5-18 5.6.2 Alternative Mobility Targets ...... 5-19 5.6.3 IAMP Adoption Process ...... 5-21

6. PUBLIC INVOLVEMENT ...... 6-1 6.1 Stakeholders ...... 6-1 6.2 Outreach Summary ...... 6-1 6.2.1 Project Introduction ...... 6-2 6.2.2 Alternatives Development ...... 6-2 6.2.3 Preferred Alternative Selection ...... 6-3 6.2.4 Preferred Alternative Refinement and Phase 1 ...... 6-4

7. REFERENCES ...... 7-1

LIST OF FIGURES 1-1 IAMP Study Area ...... 1-2 2-1 Existing Land Use ...... 2-2 2-2 Marion County Zoning...... 2-3 2-3 Intersection Lane Configurations ...... 2-7 2-4 FEMA Floodplains and Goal 5 Resources ...... 2-10 2-5 Soils, Wetlands, and Streams ...... 2-12 2-6 Hazardous Materials Details ...... 2-16 2-7 Archaeological Resources ...... 2-18 3-1 2018 30th Highest Annual Hour Traffic Volumes – All Vehicles ...... 3-3 3-2 2018 30th Highest Annual Hour Traffic Volumes – Heavy Trucks Only ...... 3-4 3-3 2042 Design Hour Traffic Volumes – All Vehicles ...... 3-10 3-4 2042 Design Hour Traffic Volumes – Heavy Trucks Only ...... 3-11 4-1 Aurora Donald Interchange Alternatives Selection Process ...... 4-2 4-2 TDI Concept ...... 4-7 4-3 CR-2 Concept ...... 4-10 4-4 CR-4 Concept ...... 4-11

October 2020 │ 274-3012-031 iii I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 TABLE OF CONTENTS (CONTINUED) 4-5 DIR Concept ...... 4-14 4-6 FDR Concept ...... 4-17 4-7 FDS Concept ...... 4-20 4-8 DGR Concept ...... 4-23 4-9 SPI Concept ...... 4-25 4-10 DDI Concept ...... 4-28 4-11 SPI Concept Alternative ...... 4-30 4-12 SPI Concept Cross Sections ...... 4-31 4-13 DDI Concept Alternative ...... 4-32 4-14 DDI Concept Cross Sections ...... 4-33 5-1 Preferred Alternative Refinement and Phasing ...... 5-1 5-2 Preferred Alternative – June 2019 ...... 5-3 5-3 Refined Preferred Alternative ...... 5-5 5-4 Refined Preferred Alternative Cross Section ...... 5-6 5-5 Phase 1 Improvements...... 5-10 5-6 Phase 1 Alternative Cross Section ...... 5-11 5-7 Phase 1 Alternative – Expected intersection v/c and vehicle queue lengths for 2022 (opening day) and 2030 ...... 5-12 5-8 Preferred Alternative – Phase 1 and Phase 2 Improvements ...... 5-14 5-9 Preferred Alternative Access Management Plan ...... 5-15 5-10 Phase 1 Access Management Plan ...... 5-18

LIST OF TABLES 2-1 Demographic Summary ...... 2-4 2-2 Forecast Population ...... 2-4 2-3 Roadway Jurisdiction and Functional Classifications ...... 2-5 2-4 Nearest Access Points to East and West of Interchange ...... 2-8 3-1 Existing (2018) 30th Highest Hour Traffic Operations at Study Intersections ...... 3-5 3-2 Existing (2018) 30th Highest Hour Traffic Operations on I-5 ...... 3-6 3-3 Intersection Crash Ratesa (2012–2016) ...... 3-8 3-4 Future (2042) No-Build Design Hour Traffic Operations at Study Intersections ...... 3-12 3-5 Future (2042) No-Build Design Hour Traffic Operations on I-5 ...... 3-13 4-1 TDI Traffic Operation ...... 4-5 4-2 CR-2 and CR-4 Traffic Operation ...... 4-8 4-3 DIR Traffic Operation ...... 4-12 4-4 FDR Traffic Operation ...... 4-15 4-5 FDS Traffic Operation ...... 4-18 iv October 2020 │ 274-3012-031 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 TABLE OF CONTENTS (CONTINUED)

4-6 DGR Traffic Operation ...... 4-21 4-7 SPI Traffic Operation ...... 4-24 4-8 DDI Traffic Operation ...... 4-26 4-9 Alternative Evaluation ...... 4-34 5-1 Preferred Alternative 2042 Performance ...... 5-7 5-2 Phase 1 Performance ...... 5-11

APPENDICES A Background and Policy Technical Memorandum B Land Use Policy Memorandum C Land Use Existing Conditions Memorandum D Transportation Memorandum E Natural Resources Memorandum F Wetland and Waters Determination Memorandum G Parks and Recreation Existing Conditions Technical Memorandum H Level 1 Hazardous Materials Corridor Study I Road Shoulder Soil Sampling Technical Memorandum J Archaeologic Resources Memorandum K Existing and Future No-Build Traffic Conditions Technical Memorandum L Interchange Alternatives Selection Process Technical Memorandum M Preferred Alternative Technical Memorandum N Preferred Alternative Cost Estimate O Categorical Exclusion Closeout Document P Phase 1 Cost Estimate Q Phase 2 Cost Estimate R Marion County IAMP Adoption Ordinance S Stakeholder and Public Involvement Technical Memorandum

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EXECUTIVE SUMMARY Background An Interchange Area Management Plan (IAMP) is an Oregon Department of Transportation (ODOT) long-term (20+ years) transportation facility plan.1 Facility plans are one of the three levels of plans implemented by ODOT. The Oregon Transportation Plan is the highest level, providing overall goal and policy guidance for planning and development of the state’s transportation system. “Mode and topic” plans, such as the Oregon Highway Plan (OHP), are the next level and provide more specific goals and policies for the entire state highway system. Facility plans apply these system policies to a specific area or segment of highway such as an interchange. This IAMP for the I-5: Aurora Donald Interchange (Exit 278) Project (Project) establishes agreement between ODOT, local government, and stakeholders on the transportation solutions, policies, and actions needed to improve the interchange. This IAMP was prepared in accordance with the ODOT 2013 IAMP Guidelines and reflects close coordination between ODOT, Marion County, interchange area stakeholders, and the broader community. This IAMP differs from a traditional IAMP since it was developed in tandem with, not in advance of, the interchange engineering design process. The IAMP planning process served as a Project design development tool to analyze interchange area Project needs, environmental considerations, and alternative interchange design solutions along with its more traditional planning and policy focus within the IAMP study area (see Figure 1-1). This expanded scope was needed to address implementation funding made available in 2017 by the Oregon Legislature through the 2017 Keep Oregon Moving Act for the construction of a first phase (Phase 1) of the Project. This IAMP recommends both operational and physical improvements, including access management for the interchange and the county road system, along with changes to Marion County transportation policy supporting plan recommendations. Problem The Aurora Donald Interchange was built with Interstate 5 (I-5) in the 1960s. Since its construction, design criteria for the interstate, bridges, and on- and off-ramps have changed with higher typical travel speeds and increased traffic volumes. In addition to its age and outdated design, the interchange’s functional performance is substandard. Traffic volumes on the off-ramp from southbound I-5 to Ehlen Road and on Bents Road (approaching Ehlen Road) exceed intersection capacity. Additionally, the proximity of the intersections to each other (about 50 feet apart) is unsafe. Both I-5 on-ramps have an uphill grade, causing slow-speed merging of trucks onto I-5 and vehicles closely following large trucks. The grade of Ehlen Road below I-5, with significant horizontal and vertical curves, restricts sight distance at both ramp terminals, creating unsafe conditions. Land use in the area, including two truck stops, draws substantial large-truck traffic, resulting in frequent slow acceleration and turning movements that impact county roads and I-5. These congestion and safety concerns negatively impact the mobility of freight, agricultural goods, and passenger vehicles in the region.

1 Per Oregon Administrative Rule (OAR) 731-015.

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Figure ES-1. IAMP Study Area Alternative Development and Selection The process of selecting a preferred design alternative for the Aurora Donald Interchange started with an initial set of 20 different interchange design concepts that was reduced to 9 concepts after a fatal flaw analysis. After further study and review by ODOT Region 2 and continued design refinements, two interchange design alternatives emerged: a Single Point Interchange and Diverging Diamond Interchange. ODOT conducted stakeholder and public engagement to vet the two alternatives,

ES-2 October 2020 │ 274-3012-031 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 ultimately selecting the Diverging Diamond Interchange (DDI) as the Preferred Alternative based on performance and public and stakeholder feedback. Phasing of the DDI Preferred Alternative is needed to accommodate funding allocated in the Keep Oregon Moving Act. This funding represents a substantial down payment toward implementing the Preferred Alternative, but would not cover the full cost of the interchange. As a result, an initial Phase 1 project was developed. The remaining improvements to complete the Preferred Alternative comprise Phase 2 of the Project that would be implemented when funding becomes available in the future. The DDI Preferred Alternative is also known as a double crossover diamond interchange. In a DDI interchange configuration, traffic on Ehlen Road crosses to the opposite (left) side of the road while within the interchange (i.e., between the ramp intersection traffic signals). Dual traffic signals at the ramp intersections control the movement of traffic during this crossover maneuver. Upon reaching the second traffic signal, vehicles are returned to driving on the right side of the road. The DDI allows signalized ramp intersections on Ehlen Road to operate in a more efficient manner, as two-phase traffic signals. The DDI will improve safety because there are no left turns across opposing traffic and most turning movements are controlled by signals. Another safety and traffic operation benefit is that left and right turns can occur simultaneously. The DDI Preferred Alternative consists of the following Phase 1 and Phase 2 interchange improvements (see Figure 5-3). Phase 1 improvements are noted in bold. • Construct one new I-5 bridge to carry both north- and southbound traffic over Ehlen Road. • Reconstruct the I-5 travel lanes to match the new I-5 bridge. • Realign I-5 southbound lanes east, into the median, to align with the new bridge structure. • Lengthen, widen, and signalize northbound and southbound off-ramps. • Lengthen, widen, and signalize northbound and southbound on-ramps. • Construct a four-lane cross section on Ehlen Road, between the northbound and southbound I-5 ramps, with left-turn lanes to access the I-5 on-ramps and one through lane in each direction. • Realign Ehlen Road with a wider cross section under I-5 to include new signalized intersections located at the northbound and southbound ramp intersections and two lanes in each direction with bike and pedestrian facilities. • Realign Bents Road to align with Bents Court at existing Ehlen Road. • Realign Ehlen Road, west of I-5, to the north and construct a new Ehlen Road/Bents Road intersection. • Realign Dolores Way to create a new intersection farther east with Ehlen Road. The estimated construction cost of Phase 1 is $50 million, and the estimated cost of Phase 2 is $29 million.

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1. IAMP AND PROJECT DESCRIPTION 1.1 Background An Interchange Area Management Plan (IAMP) is an Oregon Department of Transportation (ODOT) long-term (20+ years) transportation facility plan.2 Facility Plans are one of the three levels of plans implemented by ODOT. The Oregon Transportation Plan is the highest level, providing overall goal and policy guidance for planning and development of the state’s transportation system. “Mode and topic” plans, like the Oregon Highway Plan (OHP), are the next level, providing more specific goals and policies for the entire state highway system. Facility Plans then apply these system policies to a specific area or segment of highway such as an interchange. An IAMP establishes agreement with a local government and stakeholders about what transportation projects, solutions, or land use policies and actions are needed in an interchange area to improve the facility. State rules3 require the preparation of an IAMP for any new or significantly reconstructed interchange to preserve and protect the investment of state resources to improve safety and operation of the facility. In addition, OHP policies direct ODOT to plan and manage interchange areas for safe and efficient operation. IAMPs help balance and manage transportation and land use policy and protect existing and future state investments in the transportation system. This IAMP was prepared in accordance with ODOT’s 2013 IAMP Guidelines and reflects close coordination between ODOT, Marion County, interchange area stakeholders, and the broader community. 1.2 Study Area The Aurora Donald Interchange study area is coterminous with the Marion County Interchange District (ID) Zone as shown on Figure 1-1. The County ID Zone is smaller than the IAMP study area which was used for existing conditions inventory and impact analysis. The IAMP study area shown on Figure 1-1 includes all land adjacent to potential project improvement areas, and land that is likely to affect or be affected by the interchange improvements. The management area focused the development and evaluation of IAMP alternatives and delineated the area where implementation applies.

2 Per Oregon Administrative Rule (OAR) 731-015 3 Per OAR 734-051-0155

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Figure 1-1. IAMP Study Area 1.3 Purpose This IAMP was prepared in anticipation of the reconstruction of the Exit 278 interchange on Interstate 5 (I-5), the Aurora Donald Interchange, located at Ehlen Road between Donald to the west and Aurora to the east in Marion County, Oregon. The reconstruction will address existing and future safety issues and congestion. The Aurora Donald Interchange is approximately 7 miles north of the Woodburn Interchange, 4 miles south of the Charbonneau Interchange, and 6 miles southwest of the City of

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Wilsonville. The interchange serves the communities of Aurora, Donald, St. Paul, Canby, Barlow, and Butteville. It provides connections to the Aurora State Airport, Newberg, and the OR 18/99W corridor, Yamhill County, and the Oregon Coast. The interchange also provides access to and from rural agricultural operations and Champoeg State Park. Several businesses are located at the interchange, including two large truck stops, a recreational vehicle park, and a service station serving trucks and local vehicles, recreational traffic, and I-5 users. Additional businesses within the study area include truck services, such as truck washing, repair, and tire maintenance, recreational vehicle storage, screen printing, custom home developers, auto parts retail, concrete accessories and supplies, countertop manufacturers, and agricultural supplies. Existing traffic volumes at the interchange exceed capacity, and traffic congestion affects safe and efficient vehicle movement to and from I-5. ODOT prepared this IAMP to ensure operation of the interchange area is safe and efficient, to preserve the state’s major investment in reconstruction of the interchange, and to minimize the need for future interchange improvements. This IAMP differs from a traditional IAMP; plan development was used as a project development tool to analyze interchange area project needs and alternative designs along with the more traditional planning and policy focus of an IAMP. This expanded scope was needed to address implementation funding made available in 2017 by the Oregon Legislature through the 2017 Keep Oregon Moving Act. The Act allocated $25 million toward the construction of a first phase (Phase 1) of the Aurora Donald Interchange Project. The plan recommends both operational and physical improvements, including access management at the interchange and on the county road system, along with recommended changes to County transportation policy supporting the plan recommendations. This IAMP and reconstruction of the interchange will improve how the interchange area functions, accommodate long-term capacity needs of the system, and support community needs. The land use and access control measures established in the IAMP will provide property owners and developers with an additional level of certainty on the types of development and level of transportation improvements that can be expected to maintain safe and efficient operation at the interchange. 1.4 Problem Statement The Aurora Donald Interchange was built with the interstate in the 1960s. Since its construction, design criteria for the interstate, bridges, and on- and off-ramps have changed with higher typical travel speeds and increased traffic volumes. In addition to its age and outdated design, the interchange’s functional performance is substandard. The Marion County 2005 Rural Transportation System Plan (TSP) Sub-Area Plan for the interchange area notes that traffic volumes on the off-ramp from southbound I-5 to Ehlen Road and on Bents Road (approaching Ehlen Road) exceed the capacity of those intersections at certain hours of the day. Those intersections function at level of service (LOS) F and do not meet Marion County’s or the OHP’s mobility target (volume-to-capacity ratio [v/c] = 0.85). Additionally, the proximity of the intersections to each other (about 50 feet apart) is unsafe. Congestion and operation problems at these two intersections have increased since completion of the TSP. Another factor contributing to traffic congestion is land use within the interchange area. Two truck stops draw substantial large truck traffic, resulting in frequent slow acceleration and turning movements that impact county roads and I-5. Traffic frequently backs up on both off-ramps and occasionally onto I-5. Traffic on the off-ramp from northbound I-5 is approaching capacity for the intersection with Ehlen Road, with similar mobility and safety concerns at the southbound exit. The vehicle delays caused by

October 2020 │ 274-3012-031 1-3 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 these intersection deficiencies are detrimental to the mobility of freight, agricultural goods, and passenger vehicles in the region. Both I-5 on-ramps have an uphill grade, causing slow-speed merging of trucks onto I-5 and vehicles closely following large trucks. The grade of Ehlen Road below I-5, with significant horizontal and vertical curves, restricts sight distance at both ramp terminals, creating unsafe conditions. 1.5 Goals and Objectives Through collaboration with Marion County and key stakeholders, ODOT developed the following goal statement for the IAMP and interchange reconstruction project: The goal of the Aurora Donald Interchange IAMP and reconstruction project is to improve safety, operations, and capacity problems while maintaining efficient movement of passenger and freight traffic through the interchange area with a phased solution that will accommodate the Phase 1 funding provided in the Keep Oregon Moving Act. Based on this goal, and in order to be consistent with OHP policy4 and the IAMP problem statement, the objectives of the IAMP are to: • Protect long-term safety and operations of the interstate and county road network. • Build on the work of the Marion County Rural TSP Sub-Area Plan for the Aurora Donald Interchange area. • Protect the investment in I-5 and the interchange and maintain the function of the interchange. • Plan for future management of the interchange and adjacent land uses within the interchange management area. • Develop alternatives that can be constructed in phases to accommodate Keep Oregon Moving Act funding and future development and limit “throw-away” improvements to the maximum extent feasible. • Develop an access management plan that provides for safe and acceptable operations on the transportation network and that moves toward meeting the access spacing standards prescribed in the OHP. See Appendix A for the Background and Policy Technical Memorandum.

4 Policy 3C of the OHP states, “it is the policy of the State of Oregon to plan for and manage grade-separated interchange areas to ensure safe and efficient operation between connecting roadways.”

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2. EXISTING CONDITIONS AND INVENTORY ANALYSIS 2.1 Introduction This chapter describes existing conditions in the IAMP study area with respect to land use, transportation facilities, natural resources, hazardous materials, and cultural resources. Several memoranda were prepared; each provides an in-depth analysis of one of the topics. The memos are included as appendices, and they are summarized in the sections that follow. 2.2 Land Use This section review land use, plans, regulations, and policies that affect the study area. The Land Use Policy Memorandum (see Appendix B) presents a full review of existing plans, regulations, and policies that affect transportation planning in the IAMP study area.

2.2.1 Existing Land Use and Zoning The Aurora Donald Interchange is located in unincorporated Marion County. There are a variety of land uses in the study area ranging from agricultural and commercial to a recreational vehicle (RV) resort. The commercial uses in the area are primarily for travelers using I-5 and include gas stations, travel stops, a truck wash, and auto repair shops. Additionally, there are a few businesses not associated with travel (e.g., custom home sales). The IAMP study area is approximately 297 acres. The approximate coverage of current uses, based on the site’s primary use, are as follows: • Agriculture and open space – 210 acres • Commercial – 77 acres • RV resort – 10 acres The Fargo Interchange Service District, established in 1992, provides sewer service to the study area. Provision of sewer service can accommodate more development, as it is typically an urban service. There are 41 tax lots located in the study area; not all the tax lots are entirely within the boundary of the study area (see Figure 1-1). The land use existing conditions memorandum in Appendix C includes an analysis of all of the tax lots noting acreage, building area, zoning, comprehensive plan designation, use, and ownership. Figure 2-1 shows existing land use in the study area as classified by current assessor’s office data, supplemented by site visit observation. The County’s Rural Zoning Code includes two zones, ID and Exclusive Farm Use, and two overlay districts, Airport and Limited Use, that cover the IAMP study area. Figure 2-2 shows the current zoning within the study area. Descriptions of the applicable zones and overlays in the study area are detailed below.

2.2.1.1 Interchange District Zone The purpose of the ID Zone (MCC Chapter 17.150) is to “provide for the location of needed highway service commercial facilities at the interchanges between the controlled access highways and

October 2020 │ 274-3012-031 2-1 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 intersecting arterial roads.” This zone generally allows commercial uses, industrial uses and RV parks. A full list of uses and development standards for the ID Zone is provided in Appendix C.

2.2.1.2 Exclusive Farm Use Zone The purpose of the Exclusive Farm Use zone (EFU; MCC Chapter 17.136) is to provide areas for continued practice of commercial agricultural areas that are generally well suited for large-scale farming. Non-farm uses in the EFU zone must abide by the criteria and standards in OAR 660-033-0130 to minimize impact from potentially conflicting non-farm uses. The minimum parcel size in the EFU zone is 80 acres; however, for non-farm uses, the minimum size standard states the parcel “shall only be as large as necessary to accommodate the use and any buffer area needed to ensure compatibility with adjacent farm use.” A full list of uses and development standards for the EFU zone is provided in Appendix C.

Figure 2-1. Existing Land Use

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Figure 2-2. Marion County Zoning

2.2.1.3 Airport Overlay Zone The Aurora State Airport is located 1.6 miles northeast of the interchange, and the Marion County Airport Overlay zone applies to the entire IAMP study area. The airport overlay has three districts: the Airport Development District, the Horizontal Surface District, and the Conical Surface District (see Figure 2-4 of Appendix C). The IAMP study area is in both the Aurora State Airport’s Horizontal Surface District and Conical Surface District. The purpose of the Airport Overlay Zone (MCC Chapter 17.177) is to minimize potential dangers or conflicts with use of aircraft at public airports based on the airport’s master plan. The provisions of the overlay are intended to comply with Federal Aviation Administration regulations and other applicable state and federal regulations for air navigation and related hazards. More information about the Airport Overlay Zone is provided in Appendix C.

2.2.1.4 Limited Use Overlay Zone One property in the IAMP study area is designated with the Limited Use (LU) Overlay Zone (MCC Chapter 17.176); see Figure 2-2. The property is 28 acres with frontage on both Ehlen Road and Bents Road in the northwest quadrant of the interchange area. The general purpose of the LU Overlay Zone is to “reduce the

October 2020 │ 274-3012-031 2-3 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 list of permitted or conditional uses in a zone that are suitable for a particular location.” The Marion County Assessor’s property records indicate there are no permanent buildings or dwellings on the site. To avoid undesirable or conflicting uses, the LU Overlay Zone can be used to identify the appropriate uses for a property, or properties, by requiring conditional use permits for uses normally permitted in the zone. The LU Overlay designation may also be applied to comply with use limitations for a goal exception required by OAR 660-004. The ID-LU property has a specific set of conditions of approval for the site detailed in a series of land use cases from Marion County and appeal rulings through the Oregon State Land Use Board of Appeals. Appendix B provides details of the conditions of approval. Generally, the uses for the site are limited to specific permitted accessory uses to the travel center/truck stop located to the east across Bents Road, and any development on the site is subject to the relocation of Bents Road to the west, such that it intersects Ehlen Road across from Bents Court.

2.2.2 Growth and Demographics Demographic information related to historical and forecast population growth was evaluated to provide an understanding of forecast transportation needs. The study area includes three U.S. Census Bureau block groups. The following table summarizes demographic characteristics for these block groups (see Table 2-1).

Table 2-1. Demographic Summary

Total Population Median Income Poverty Status Minority Marion County 330,453 $53,828 16% 18% BG 1, CT 102.01 1,168 $89,886 5% 5% BG 2, CT 102.01 1,521 $63,472 10% 23% BG 1, CT 102.02 1,227 $53,173 0% 2% B19013: Median household income in the past 12 months (in 2017 inflation-adjusted dollars), households. C17002: Ratio of Income to Poverty Level in the past 12 months, population for whom poverty status is determined. B02001: Race, total population. Source: U.S. Census Bureau, 2013-2017 American Community Survey 5-Year Estimates

Portland State University’s (PSU) Population Research Center conducted a Coordinated Population Forecast for Marion County, areas within urban growth boundaries (UGB) for Aurora and Donald, and unincorporated areas outside UGBs for the time period from 2017 to 2067. The study shows that Marion County’s population has been steadily growing from 2000 to 2010 with an average annual growth rate of 1 percent. The City of Donald has the highest average annual growth rate of 4.9 percent between 2000 and 2010. The study also forecast that Marion County will grow at a faster pace in the near term (2017 to 2035) than in the long term (beyond 2036). The PSU study reports forecast populations as shown in Table 2-2. Detailed information from this study and the Cities of Donald and Aurora are included in Appendix C.

Table 2-2. Forecast Population

2035 2067 Marion County 405,352 513,142 Aurora UGB 1,321 1,622 Donald UGB 1,555 2,150

Source: Population Research Center

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2.3 Transportation Facilities

2.3.1 Road Facilities The ownership, functional classification, and other special designations of area roadways are listed in Table 2-3. The functional classifications of the primary roadways in the study area (I-5 and Ehlen Road) indicate that the primary objective of these corridors is to efficiently move high volumes of traffic over long distances. Federal and state designations of I-5 as a truck/freight route highlight the national and local importance of accommodating the movement of large vehicles, which is consistent with many of the land uses present in the interchange area.

Table 2-3. Roadway Jurisdiction and Functional Classifications

Roadway Name Jurisdiction Functional Classification Other Designations Interstate 5 (I-5) Oregon Dept. of Interstate Highway National Highway System (NHS) Transportation National Network (Federally designated Truck Route) State Freight Route Reduction Review Route Ehlen Rd Marion County Principal Arterial (west of I-5) Primary Detour Route (west of I-5) Arterial (east of I-5) Primary and Alternate Detour Route (east of I-5) Bents Rd Marion County Minor Collector Bents Ct Marion County Local Road Dolores Wy Marion County Local Road Sources: 1999 OHP as amended May 2015. Marion County Rural TSP, 2005.

2.3.1.1 Interchange Conditions and Geometric Characteristics Typical geometric characteristics of area roadways are listed in Appendix D, Table 2. All roadways have one travel lane in each direction. The only turn lanes in the study area are at the intersection on Ehlen Road with Bents Court, where there is a westbound left-turn lane on Ehlen Road and separate northbound left- and right- turn lanes on Bents Court. The wide flared ends of the I-5 northbound and southbound off-ramps as they meet Ehlen Road are often used as if they were separate left- and right-turn lanes, but they are not formally designed or striped as such. Intersection lane configurations are illustrated in Figure 2-3.

2.3.1.2 Traffic Controls Traffic control types present in the study area are illustrated in Figure 2-3, including locations of stop signs and posted speeds. There are no traffic signals in the study area, and all minor street approaches are stop- controlled. Consistent with the functional classifications, posted speeds on I-5 and Ehlen Road remain fairly high, with the posted speed on Ehlen Road only dropping to 35 mph through the interchange area. Even though Bents Road is classified as a minor collector, the posted speed remains high at 55 mph. There is a traffic separator in the median of Ehlen Road, approximately 2 feet wide and 350 feet long, that prohibits left turns to and from the Flying J Travel Center driveway on the south side of the road. On-street parking is not designated on any study area roadway, but trucks have been observed parking on the shoulders of the I-5 ramps. No Parking signs have been posted on Bents Court, Bents Road, and Ehlen Road (west of I-5).

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2.3.1.3 Access Oregon Administrative Rule (OAR) 734-051 defines the State’s role in managing access to highway facilities in order to maintain functional use and safety and to preserve public investment. The rule includes spacing standards for varying types of state roadways and criteria for granting right of access and approach locations onto state highway facilities. Amendments to OAR 734-051 have been adopted in 2010, 2011, 2012 and 2013. Senate Bill 408, which passed in the 2013 legislative session and became effective January 1, 2014, addressed three priorities: existing approaches (private driveways) without ODOT’s written permission; access management in highway facility plans; and access management in highway project delivery. Within the study area, Ehlen Road has 16 private access points (driveways) and 3 public access points (streets), in addition to the 2 interchange ramp terminals. Many of the private access points appear to serve low volumes of traffic and 6 of them are only for field access. ODOT’s interchange crossroad access spacing standards requirements are listed below (all distances measured from the nearest ramp terminal):5 • 1,320 feet to the first approach on the right (when driving away from the interchange), right-in/right-out only • 1,320 feet to the first intersection where left turns are allowed • 1,320 feet between the last approach road (when driving toward the interchange) and the start of the taper for the on-ramp

5 1999 Oregon Highway Plan, as amended May 2015, Appendix C Table 17: Minimum Spacing Standards Applicable To Freeway Interchanges with Two-Lane Crossroads, p. 213.

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Figure 2-3. Intersection Lane Configurations (Source: Appendix D, DKS Technical Report,)

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Table 2-4 describes the closest public and private access points along Ehlen Road relative to the I-5 ramp terminals to the east and west. Appendix D provides a detailed table with distances to all access points.

Table 2-4. Nearest Access Points to East and West of Interchange

Distance from Nearest I-5 Ramp Terminal Side of Tax Lot Number (ft) Road Width (ft) Turn Movements Directly Served Type of Use East of I-5 325 South 34 Unrestricted N/A Dolores Wy 200 North 45 Unrestricted 041W10 00600 Field access West of I-5 75 North 45 Unrestricted N/A Bents Rd 475 South 175 Right-in/right-out only 041W09DD00600 Flying J Travel Center

2.3.2 Pedestrian and Bicycle Facilities Most facilities present for people walking and biking are in the form of roadway shoulders. The Marion County Rural TSP shows Ehlen Road as a corridor with shoulders more than 4 feet wide, but widths vary throughout the study area. Bents Road also has paved shoulders, but they are generally less than 4 feet wide. There are two locations where sidewalks are present. One is on the east side of Dolores Way, and the other is along both sides of Bents Court. The sidewalks on Bents Court have ramps, which appear to be ADA-compliant.

2.3.3 Public Transit Facilities There are no transit stops within the study area. Cherriots/SMART6 Route 1X (an express route) travels through the area on I-5, connecting Salem and Wilsonville, Mondays through Fridays (approximately 5:45 a.m. to 8:00 p.m.). Similarly, the Oregon POINT bus, Greyhound, and the Bolt Bus also travel along I-5, but do not stop in the study area. While there are no transit stops within the study area, this interchange area was identified by Marion County as a possible future site for a park and ride (Marion County 2005). 2.4 Natural Resources

2.4.1 Physical Setting The IAMP study area is located in the northern end of the Willamette Valley, which is characterized by relatively low topographic relief with some areas of buttes and valleys containing moderate slopes. The valley is bordered to the east by the foothills of the Cascade Mountains, to the west by the Oregon Coast Range, and to the south

6 SMART = South Metro Area Regional Transit

2-8 October 2020 │ 274-3012-031 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 by the Calapooya Mountains. The Willamette River meanders through the valley from south to north. Faults exist on the eastern and western margins of the Willamette River basin. Sedimentary deposits have filled the Willamette Valley and generally consist of conglomerate, gravel, sand, silt, and some clay from volcanic, fluvial, and lacustrine material. Quaternary alluvial deposits cover much of the surface within the vicinity of the subject property area. These sedimentary deposits overlie Miocene basalt flows of the Columbia River Basalt Group. The Columbia River Basalt Group overlies lava flows and volcanic breccias of Oligocene age (Ma et al. 2009). The study area is located at an elevation of 193 feet above mean sea level. Topography is primarily flat, with the exception that Ehlen Road passes beneath I-5 below grade. The surrounding Willamette Valley also primarily consists of low topographic relief but includes many gently sloping hills and valleys. Shallow soil in the area consists of fine-grained soils that include silts, loams, and clays. Depth to groundwater in the vicinity of the project area is expected to range from approximately 20 to 40 feet below ground surface. Groundwater flow in this portion of the Willamette Valley is highly variable and can be significantly impacted by local creeks and rivers. The nearest surface water body is Senecal Creek, approximately 0.5 mile to the south. The Willamette River lies approximately 3 miles to the northwest.

2.4.2 Floodplains There are no Federal Emergency Management (FEMA)-mapped floodplains with the study area (see Figure 2-4).

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Figure 2-4. FEMA Floodplains and Goal 5 Resources

2.4.3 Surface Waters and Wetlands

2.4.3.1 Surface Waters One mapped stream is located within the study area. This unnamed stream (Reach Code 17090009010504) is a tributary to Senecal Creek, which flows approximately 2,000 feet south of the study area boundary. The unnamed stream is classified in the National Wetlands Inventory as a riverine (R4SBC) reach near Ehlen Road and as a freshwater forested/shrub wetland (PFO1C) reach between the upstream reach and its confluence with Senecal Creek. Field observation in May 2019 indicated that this unnamed tributary appears to receive hydrology from surface runoff, flow from roadside ditches, and groundwater discharge.

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Roadside ditches are present along much of Ehlen Road and Bents Road in all quadrants of the study area (see Photos 1 through 6 in Appendix E). One stormwater pond apparently associated with the Travel Centers of America fueling station is present within the northwest quadrant (see Photo 7 in Appendix E). A pond of unknown origin, apparently associated with Westside Concrete Accessories, is present in the southwest quadrant (see Photo 8 in Appendix E).

2.4.3.2 Wetlands According to the U.S. Fish and Wildlife Service (USFWS) National Wetlands Inventory (2018)7, a freshwater pond polygon is located near the north-central extent of the study area. Based on recent aerial photos, this location is now a paved parking area for tractor-trailers (see Figure 2-5). No local wetland inventory has been prepared for this area. A subsequent wetland determination was conducted at the site with field investigations in 2019 and 2020. Scientists walked the entire study area (with the exception of property owned by Aurora Energy due to a lack of a signed right-of-entry form). Several wetlands and roadside ditches were determined to be present within the study area, though the wetlands were not classified or delineated. See Appendix F for additional wetland information. Approximately 18 percent of the study area is classified as Concord silt loam which is rated as a hydric soil (NRCS 2019)8 (see Figure 2-5). The remaining soils are not classified as hydric. Additional detail is provided in Appendix F.

7 USFWS National Wetlands Inventory, https://www.fws.gov/wetlands/data/mapper.html

8 Natural Resources Conservation Service Web Soil Survey, https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm

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Figure 2-5. Soils, Wetlands, and Streams

2.4.4 Biological Resources and Habitat

2.4.4.1 Habitat During a site visit conducted on January 22, 2019, the study area was predominantly agricultural with development consisting of roadways and fueling stations along with small areas of long-term residential

2-12 October 2020 │ 274-3012-031 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 camping and commercial and light-industrial development. The agricultural fields consisted of a low grassy groundcover in the northwestern quadrant of the study area (Photo 1 in Appendix E) and unidentified tree saplings amongst low grassy groundcover in the northeastern quadrant (Photos 2 and 3 in Appendix E). A small grove of hardwood and conifer trees was present between the field and I-5 in the northeastern quadrant. The fields in the southeastern quadrant consisted of low grassy groundcover, while the drainage area of the tributary to Senecal Creek appeared to be dominated by Douglas-fir (Pseudotsuga menziesii), invasive English ivy (Hedera helix), and Armenian (Himalayan) blackberry (Rubus armeniacus) (Photos 4 and 5 in Appendix E). A small grove of 24- to 36-inch-diameter Douglas-fir trees is located adjacent to the RV resort (Photo 6 in Appendix E). Much of the southwestern quadrant consisted of developed areas with ornamental vegetation and grassy lawns.

2.4.4.2 Special Status Species A review of existing information related to fish and wildlife distribution and habitat within and surrounding the study area included the following: • USFWS Information Planning and Conservation (IPaC) database – Trust Resources Report • USFWS Environmental Conservation Online System (ECOS) Critical Habitat for Threatened and Endangered Species • StreamNet: Fish Data for the Northwest Interactive Mapper In addition, the Oregon Biodiversity Information Center (ORBIC) produced a database search for rare, threatened, and endangered plant and animal records for species that may occur within a 2-mile radius of the study area. The ORBIC database search showed two federally listed species: Upper Willamette River (UWR) Chinook salmon (Oncorhynchus tshawytscha) and UWR steelhead (O. mykiss). The ORBIC database search revealed three special status species recorded within a 2-mile radius of the study area: • Western painted turtle (Chrysemys picta bellii) – Federal: None; ORBIC: Sensitive - Critical • Oregon giant earthworm (Driloleirus macelfreshi) – Federal: Species of Concern; ORBIC: Sensitive9 • Fungus (Tuber quercicola) – Federal: None; ORBIC: Review Based on the off-site data collection efforts and a January 22, 2019, site visit to assess species presence and habitat conditions within the study area, suitable habitat for Oregon special status species is not present within the study area, and no State of Oregon special status species are known or expected to occur in the study area. There are no critical habitats designated within the study area, and no ESA-listed species occur in the study area (see Table 1 in Appendix E). Consultation with the National Marine Fisheries Service through the Federal Aid Highway Program programmatic biological opinion process will be required. The consultation would consider potential effects due to changes in base and peak stream flows caused by new impervious surface and potential impacts to water quality within the study area as well as in waters downstream of the study area discharges (including Senecal Creek, Mill Creek, the Pudding River, the Willamette River, and the Columbia River).

9 The status of Oregon giant earthworm and the fungus Tuber quercicola are from those listed in the ORBIC (2019) report. Recent reclassifications show no official status for these species, other than federal species of concern and ORBIC status of “Threatened or Endangered throughout Range” for the earthworm, and ORBIC status of “Review” for the T. quercicola (ORBIC 2016).

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2.4.4.3 Critical Habitat The nearest critical habitat, not including the salmonid critical habitat in the Pudding River, is that of Kincaid’s lupine (Lupinus sulphureus ssp. kincaidii) located approximately 25 miles west of the study area, and of Fender’s blue butterfly (Icaricia icarioides fenderi) located approximately 26 miles to the south (USFWS ECOS). Therefore, critical habitats under the jurisdiction of USFWS would not be impacted by the proposed project. Additional detail for biological resources and habitats is provided in Appendix E.

2.4.5 Open Space and Parks The Aurora Acres RV Resort and associated grassy forested open space and picnic area are within the study area. The RV park and open space area are in private ownership. There are no publicly owned parks or other recreation resources, including trails and wildlife refuges within the study area or within one mile of the study area. The interchange is one of many ways to access Champoeg State Park, approximately 4 miles to the west of I-5, but interchange improvements will not affect the park. Additionally, there are no planned parks or recreation projects within or near the study area identified in the 2010 Marion County Parks Master Plan (see Appendix G). 2.5 Hazardous Materials Parametrix conducted a Level I hazardous materials corridor study for the project in general accordance with ODOT and American Association of State Highway Transportation Officials guidance. Full details along with associated site photos can be found in Appendix H. The hazardous materials corridor study was conducted to identify potential sources of hazardous substances and/or petroleum products that may include an existing release, a past release, or a material threat of a release of hazardous substances to soil, groundwater, or surface water, and evaluate if the releases could affect the environment or create significant construction impacts. A review of historical information indicated that the project corridor was generally undeveloped until the 1950s when I-5 was constructed, including the on- and off-ramps at Exit 278. Several businesses are located within the immediate vicinity of the interchange, including two large truck stops, an RV park, and a service station. These facilities were generally developed in the 1980s. Recognized environmental conditions (RECs) identified during the historical data review include the operation of the fueling areas and associated activities adjacent to the interchange for more than 35 years (see Figure 2-6 and Appendix H). • Several sites in the vicinity of the project corridor were identified on regulatory databases, including on the Oregon Department of Environmental Quality’s (DEQ) Environmental Cleanup Site Information (ECSI) and Leaking Underground Storage Tank (LUST) databases, and the Spills database. Three sites were identified as having the potential to have impacted the project corridor and were identified as RECs.

➢ The Travel Center of America truck stop is located immediately to the northwest of the interchange. The site has had known past releases to soil, groundwater, and surface water. The property is listed on the DEQ ECSI and LUST databases, and has had a number of spill incidents and known stormwater impacts. Based on the past incidents and operational practices, as well as its close proximity to the interchange area, there is some potential for residual subsurface conditions on or near the property that could impact future constructions activities. Thus, the Travel Center of America site represents a REC to the project corridor.

➢ The Leathers Oil site is located at the current Flying J/Pilot Travel Center property to the southwest of the interchange. The property is listed on the DEQ LUST database and has had a number of spill incidents. Investigation and remedial actions have included a UST decommissioning, groundwater

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monitoring, and on-site soil treatment/disposal. The site received a No Further Action (NFA) letter from DEQ in 2014. However, based on the extensive history of environmental issues at the property, proximity to the project corridor, and known residual contamination, the presence of the former Leathers Oil site is considered a potential REC to the project corridor.

➢ In addition to the above facilities, one spill site was identified as a REC and is listed in the DEQ ECSI database. This is the Younger I-5 @ Donald near MP 278 site. In September 1997, approximately 1,700 gallons of diesel and 4,000 gallons of gasoline were released as a result of an accident and fire on a cargo truck and trailer on I-5 near Exit 278. Investigation and monitoring was conducted under oversight from DEQ in the late 1990s. The site subsequently received an NFA determination from DEQ in 2001. However, based on the spill volume and extent, there is some potential for residual soil contamination in the vicinity of the road shoulder or other areas. While the potential impact is likely low, the past release incident represents a potential REC to the project corridor. A site reconnaissance was conducted in January 2019. No significant RECs, other than those identified above, were documented during the site reconnaissance. A road shoulder soil sampling memorandum was prepared presenting the results of road shoulder soil sampling conducted in November 2019. It was subsequently approved by ODOT (see Appendix I). No samples exceeded the 100 mg/kg threshold for lead. One or more polycyclic aromatic hydrocarbons (PAH) constituents were detected above the method detection limit in 18 of 54 samples collected.

2.5.1 Recommendations The following recommendations are based on the conclusions of the hazardous materials corridor study: The completion of a Level 2 Preliminary Site Investigation (PSI) should be considered for the project corridor. Specifically, the presence of known and potential environmental issues identified at the Travel Center of America and Flying J properties have some potential to have impacted subsurface conditions in the corridor and future construction and/or acquisition areas. The Level 2 PSI should include characterization of soil and/or groundwater in areas potentially impacted by construction, particularly along the south and east boundaries of the Travel Center of America and along the north and east boundaries of Flying J property.

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Figure 2-6. Hazardous Materials Details 2.6 Cultural Resources

2.6.1 Historic Resources The Oregon Historic Sites Database (accessed through the State Historic Preservation Office website) lists historic Oregon properties included in the National Register of Historic Places (NRHP) and historic resources that have been previously identified. The database was queried to determine if historic resources are present within the study area, resulting in the identification of one resource. The Big Eddy-Chemawa No. 1 (Historically Oregon City-Chemawa No. 3) Bonneville Power Administration Transmission Line was constructed in 1955. According to

2-16 October 2020 │ 274-3012-031 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 the Bonneville Power Administration (BPA) Pacific Northwest Transmission System Multiple Property Documentation Form, a document outlining the BPA system’s eligibility for listing in the NRHP, the transmission line in the project area meets the criteria for eligibility and is therefore eligible for listing in the NRHP.

2.6.2 Archaeological Resources An archaeological resources review of the study area identified both pre-European and historic-period use within and near the study area. The study area was inhabited by members of the Ahantchuyuk tribe, referred to as the French Prairie Indians or Pudding River Indians, a band within the Kalapuya. They practiced a subsistence round of seasonal fishing, hunting, and management of prairies, thus areas within the former prairie and creeks and wet meadows within the study area could have been occupied by groups during various times of the year. A General Land Office map from 1852 indicates a portion of Ehlen Road (on the east side of present day I-5) was roughly in place as a wagon road, and much of the land to the northeast, within and near the study area, belonged to a French-Canadian trapper and his Chinook wife, with a building near present day Bents Road. By 1878, the Ehlen Road alignment was established largely where it is today, and members of the Aurora Colony were the primary landowners, with C.H. Ehlen listed as a primary owner. Bents Road is first visible on a United States Geological Survey (USGS) map from 1923, and by 1936 an aerial image shows clusters of farmstead buildings within the study area. Finally, a USGS map from 1956 shows I-5 had been constructed and shows Bents Road displayed with its former name, Fargo (see Appendix J for maps and aerials). A literature review identified one mapped archaeological resource within the study area. However, the location and potential physical remains of the resource had not been field verified, and the site had not been evaluated for listing in the NRHP at the time of the initial inventory. Based on the cultural and environmental setting of the study area, the likelihood of encountering archaeological deposits during project work is high. The potential for scattered archaeological resources throughout the remainder of the study area is moderately high. Figure 2-7 indicates the locations with the highest likelihood of containing concentrations of archaeological resources. Appendix J provides detailed descriptions of the archaeological literature review and historic development in the study area. Since the initial inventory, pedestrian field surveys have been conducted within all areas to be disturbed by the project (with the exception of property owned by Aurora Energy due to a lack of a signed right-of-entry form). The project team completed the archaeological survey of the Aurora Donald Interchange study area in May, September, and November of 2019. The work included pedestrian survey, subsurface sampling through the excavation of shovel probes, and monitoring of geotechnical drilling locations. The project team has examined approximately 45 acres and excavated 118 shovel probes. The survey resulted in the identification of three isolated finds and two archaeological sites, all dating to the historic period. All are situated on privately owned parcels. The project team identified two sites that warrants additional archaeological investigation in support of potential NRHP listing.

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Figure 2-7. Archaeological Resources

2.6.3 Section (4f) and Section 6(f) Section 4(f) of the U.S. Department of Transportation (USDOT) Act of 1966 prohibits the Federal Highway Administration and other USDOT agencies from using land from publicly owned parks, recreation areas (including recreational trails), wildlife and water fowl refuges, or public and private historic properties, unless there is no feasible and prudent alternative to that use and the action includes all possible planning to minimize harm to the property resulting from such a use.

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The BPA towers in the study area are considered eligible for listing on the NRHP. The project, as proposed, is not anticipated to result in any adverse impacts to the towers and therefore is expected to be processed as a No Adverse Effect for Section 106 and temporary occupancy for Section 4(f). Two locations of historic debris scatter and/or farmstead features were identified during the archaeological survey and are recommended for further evaluation for their potential for listing in the NRHP. Section 4(f) applies to archaeological sites that are on or eligible for the NRHP and that warrant preservation in place, including those sites discovered during construction, thus if this archaeological site is eligible for listing, a Section 4(f) evaluation may be necessary. Although the RV resort is within the study area, to be considered a Section 4(f) Property, a park must be of national, state, or local significance and be publicly owned. The RV park is in private ownership. Thus, there are no recreation Section 4(f) resources within the study area (see Appendix G). Section 6(f) of the Land and Water Conservation Fund Act (LWCF) protects land acquired or improved with LWCF grants. Parcels purchased with LWCF grants require additional work to convert the land to a transportation use. As there are no public recreation resources within the study area, there are no properties subject to Section 6(f) funds.

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3. TRAFFIC OPERATIONS – EXISTING AND FUTURE CONDITIONS ANALYSIS This chapter documents traffic operations and safety conditions within the Aurora Donald Interchange area under 2018 existing conditions, as well as those forecast for 2042 under No-Build conditions. The 2042 No-Build scenario assumes traffic volumes have continued to grow, but that no changes have been made to the transportation system. The No-Build scenario provided a basis of comparison for the interchange design alternatives. The information in this chapter has been drawn from a series of technical memoranda provided by the ODOT Transportation Planning and Analysis Unit that document traffic data, traffic operations, and safety analysis for this project. These memoranda are provided in Appendix K for reference. 3.1 Traffic Analysis Methodology The ODOT Transportation System Monitoring Unit collected traffic counts for the study area intersections.10 The intersection traffic counts spanned a 16-hour period and accounted for up to 13 different vehicle types to identify how traffic volumes change throughout a weekday and the typical vehicle composition (i.e., percentages of passenger cars vs. trucks). Additional traffic volume data for I-5 were obtained from an Automatic Traffic Recorder (ATR) Station approximately 2.5 miles north of the Aurora Donald Interchange (ATR 03-011, at milepost 281.20). Traffic counts for the study area were adjusted to reflect conditions during the 30th highest annual hour traffic volumes (30HV) in the year 2018 (similar to what would be experienced from 4:30 p.m. to 5:30 p.m. during a summer weekday). Volumes for 2042 were forecast using a Level 2 traffic impact analysis (TIA)-level cumulative analysis methodology consistent with ODOT’s Analysis Procedures Manual (ODOT 2019). This involved building from the 2018 traffic volumes used for the existing conditions analysis by adding expected growth from regional and local sources. Operations analysis for existing and future-year conditions was conducted using tools based on the Highway Capacity Manual, Sixth Edition (HCM, TRB 2016). This included using HCS 7 software to analyze freeway mainline and merging/diverging point operations and SIDRA 8.0 software to analyze signalized and unsignalized intersection operations along Ehlen Road and Bents Road. Performance measures produced to describe system conditions included volume-to-capacity (v/c) ratios for freeway movements and v/c ratios, LOS, average vehicle delay, and 95th percentile vehicle queue lengths for signalized and unsignalized intersections. See Appendix K for more details on the methodology applied. 3.2 Existing Conditions This section describes traffic operations and safety in the study area under 2018 existing conditions, including an assessment traffic volumes in the interchange study area, quality of facilities for people walking and biking, levels of congestion, and safety issues. Descriptions of the current transportation facilities in the area can be found in Appendix K.

10 16-hour count data (6 a.m. to 10 p.m.) including vehicle speed and full federal classification collected on July 12-14, 2016. Counts at Ehlen Road and Thunderbird Drive were collected on December 4, 2018.

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3.2.1 2018 (Existing) Traffic Volumes Figure 3-1 and Figure 3-2 show the 2018 30HV traffic volumes in the study area. The 30HV typically occurs during the summer months and is the desired period to use for the analysis and design of transportation infrastructure improvements. The ODOT Transportation System Monitoring Unit collected traffic counts for the study area intersections.11 It was found that the common weekday peak hour of traffic volume through the interchange area was approximately 4:30 p.m. to 5:30 p.m. These traffic data were supplemented with ATR data in the vicinity of the interchange.

11 16-hour count data (6 a.m. to 10 p.m.) including vehicle speed and full federal classification collected on July 12-14, 2016. Counts at Ehlen Road and Thunderbird Drive were collected on December 4, 2018.

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Figure 3-1. 2018 30th Highest Annual Hour Traffic Volumes – All Vehicles

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Figure 3-2. 2018 30th Highest Annual Hour Traffic Volumes – Heavy Trucks Only

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3.2.2 Intersection Traffic Operations Traffic operations for the study intersections were analyzed using SIDRA software and HCM (TRB 2016) methodologies to determine the level of congestion experienced in 2018. The analysis was conducted at all study intersections using the seasonally factored 30HV traffic volumes for 2018 shown in Figure 3-2. Performance measures used for this analysis included v/c ratios, seconds of control delay, and LOS to align with ODOT and Marion County standards. Table 3-1 summarizes the operations analysis results for the study intersections, comparing each intersection’s performance against the adopted Marion County and ODOT mobility standards. Locations where congestion exceeds the mobility standard are highlighted for ease of reference.

Table 3-1. Existing (2018) 30th Highest Hour Traffic Operations at Study Intersections

Performance Intersection Mobility Delay Intersection Jurisdiction Control Target v/c a LOS b (sec/veh) Ehlen Rd @ Thunderbird Dr Marion County Stop signs LOS E & 0.36 B 1 v/c < 0.90 Ehlen Rd @ Bents Ct Marion County Stop signs LOS E & 0.43 C 6 v/c < 0.90 Ehlen Rd @ Flying J driveway Marion County Stop signs LOS E & 0.56 E 1 v/c < 0.90 Ehlen Rd @ I-5 Southbound ODOT Stop signs v/c < 0.85 0.73 C 15 ramp terminal/Bents Rd Ehlen Rd @ I-5 Northbound ODOT Stop signs v/c < 0.85 0.96 F 19 ramp terminal Ehlen Rd @ Dolores Wy Marion County Stop signs LOS E & 0.45 C 4 v/c < 0.90 a v/c ratio for worst movement. b LOS for worst movement. Shaded cells indicate adopted mobility standards/ targets are not met.

Analysis showed that the I-5 northbound ramp terminal with Ehlen Road failed to meet ODOT’s adopted mobility target and is very congested during the 30HV, with traffic demand nearly exceeding the capacity of the intersection. At this intersection, it is the stop-controlled northbound left turn that experiences the most delay. The I-5 southbound ramp terminal with Ehlen Road met ODOT’s mobility target, but at a v/c ratio of 0.73 it approaches the maximum target of 0.85. Field observations of congestion and vehicle queues support these findings. During the weekday PM peak hour, long northbound off-ramp queues are more common. However, both off-ramps frequently experience long vehicle queues throughout the day that back up to the high-speed freeway mainline, presenting a safety hazard. Through this analysis and observations of field conditions, the primary causes of congestion and long off-ramp queues are: • High volumes of large, heavy trucks that move slowly and require more space. • Obstructed sight lines caused by the underpass structure and Ehlen Road curves make turning left from the ramp terminals difficult.

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• The connection of Bents Road in very close proximity to the I-5 southbound ramp terminal intersection creates confusion and unexpected conflicts. • The lack of left-turn lanes on Ehlen Road at the I-5 ramp terminals.

3.2.3 Freeway Ramp Merge/Diverge Operations Operations analysis was performed for the I-5 freeway mainline in the vicinity of the interchange, including evaluations of congestion on the freeway to the north and south of the interchange, as well as at the points where traffic diverges (exits the freeway) and merges (enters the freeway). Table 3-2 summarizes the results of this analysis for the 30HV under 2018 existing conditions.

Table 3-2. Existing (2018) 30th Highest Hour Traffic Operations on I-5

Mobility Target Performance Location (v/c ratio) (v/c ratio) Southbound I-5 (listed from north to south) Southbound mainline, upstream of the interchange 0.70 0.76 Southbound off-ramp, diverge to Ehlen Rd 0.70 0.76 Southbound mainline, between the on- and off-ramps 0.70 0.68 Southbound on-ramp, merge from Ehlen Rd 0.70 0.78 Southbound mainline, downstream of the interchange 0.70 0.77 Northbound I-5 (listed from south to north) Northbound mainline, upstream of the interchange 0.70 0.68 Northbound off-ramp, diverge to Ehlen Rd 0.70 0.70 Northbound mainline, between the on- and off-ramps 0.70 0.60 Northbound on-ramp, merge from Ehlen Rd 0.70 0.66 Northbound mainline, downstream of the interchange 0.70 0.66

Highway Capacity Software (HCS) 7 software and the HCM 6 methodology were used. Shaded cells indicate adopted mobility targets are not met.

3.2.4 Crash History and Trends A comprehensive safety analysis was conducted in the study area using crash data from 2012–2016 obtained from ODOT’s Crash Analysis and Reporting Unit, in addition to information from ODOT’s Safety Priority Index System ratings, Crash Rate Tables, Roadway Departure Plan, and Intersection Safety Implementation Plan. A summary of the key findings is provided below, with the detailed analysis included in Appendix K.12

12 I-5: Aurora Donald Interchange (Exit 278) IAMP & EA Existing Conditions Analyses Summary, Oregon Dept. of Transportation, May 16, 2019.

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3.2.4.1 Crash Trends Over the 5-year period analyzed (2012–2016), there were 241 crashes within the study area, which included the I-5 mainline within one mile north and south of the interchange. Of these, 93 occurred at ramp terminal intersections. The I-5 southbound ramp terminal at Ehlen Road experienced 74 crashes, which was far more than the 19 crashes that occurred at the northbound ramp terminal. Key crash trends at these locations are summarized below. I-5 Southbound Ramp Terminal at Ehlen Road • 74 crashes between 2012 and 2016 • 98 percent of crashes resulted in only property damage or minor injuries • No crashes resulted in a fatality • 54 percent of crashes involved turning movements, 27 percent involved rear-end collisions, and 16 percent involved crossing (i.e., angle) movements • The most prevalent crash patterns are listed below:

➢ Left turns from westbound Ehlen Road to I-5 southbound (20 crashes)

➢ Left turns from I-5 southbound to eastbound Ehlen Road (16 crashes)

➢ Rear-end collisions on the I-5 southbound off-ramp (14 crashes)

➢ Crossing movements from Bents Road to the I-5 southbound on-ramp (10 crashes) I-5 Northbound Ramp Terminal at Ehlen Road • 19 crashes between 2012 and 2016 • 100 percent of crashes resulted in only property damage or minor injuries • No crashes resulted in a fatality • 68 percent of crashes involved turning movements and 21 percent involved rear-end collisions • The most prevalent crash patterns are listed below:

➢ Left turns from I-5 northbound to westbound Ehlen Road (6 crashes)

➢ Rear-end collisions on the I-5 northbound off-ramp (5 crashes)

➢ Left turns from eastbound Ehlen Road to I-5 northbound (3 crashes) I-5 Freeway Segment • 113 crashes (between mileposts 277.7 and 279.7) • 57 percent were classified as rear-end crashes • 30 percent of crashes were caused by roadway departure where a driver hit a fixed object • One fatality, three serious injuries

3.2.4.2 Intersection Crash Rate Analysis Crash rate analysis was completed for each study intersection within the study area. The results were compared to rates observed for similar facilities to identify where the frequency of crashes occurring may be higher than

October 2020 │ 274-3012-031 3-7 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 should be expected. The observed crash rate for intersections is a function of the number of crashes and the annual average daily traffic. Each intersection is grouped into a reference population based on the type of intersection control. The crash rates (crashes per million entering vehicles) for each intersection were compared to two different standards: 1. A critical crash rate, which compares performance to other similar intersections being studied in the study area. 2. A 90th percentile crash rate, which is based on similar intersections throughout the state (obtained from ODOT’s Analysis Procedures Manual Exhibit 4-1). Table 3-3 shows the crash rates for each study intersection where crashes were recorded. All observed crash rates were lower than their comparable critical crash rate and 90th percentile crash rate. However, both ramp terminals were identified as intersections in need of low-cost countermeasures in the 2012 Oregon Intersection Safety Implementation report provided by ODOT. Also, it should be noted that while the crash rate for the I-5 southbound ramp terminal intersection with Ehlen Road and Bents Road was significantly higher than the others, a comparison to crash rates for similar facilities was not possible due to the atypical five-leg configuration.

Table 3-3. Intersection Crash Ratesa (2012–2016)

Observed Crash Critical Crash 90th Percentile Intersection Name Rate Rate Crash Rate Ehlen Rd @ Thunderbird Dr 0.00 0.38 0.48 Ehlen Rd @ Bents Ct 0.03 0.34 0.48 Ehlen Rd @ I-5 southbound ramps/Bents Rd 1.30b N/A N/A Ehlen Rd @ I-5 northbound ramps 0.54 0.63 1.08 Ehlen Rd @ Dolores Wy 0.13 0.37 0.48 a Crash rates are crashes per million vehicles entering the intersection (MEV). b There is no comparable critical crash rate for a five-leg stop-controlled intersection.

3.2.5 Pedestrian and Bicycle Travel Conditions The types and locations of facilities available to serve people walking and biking through the interchange area are described in Section 2.3.2. Full discussion of pedestrian and bicycle travel conditions can be found in Appendix K. This section describes the quality of those facilities using a Level of Traffic Stress (LTS) analysis. Pedestrian Level of Traffic Stress A pedestrian LTS assessment was completed for the study area to characterize the quality of the pedestrian environment. The level of stress experienced by pedestrians was assessed by considering various roadway characteristics and applying a context-based, subjective stress rating of lowest, low, medium, or high where lowest indicates the least stressful environment and high indicates the most stressful. In general, Ehlen and Bents Roads are the most stressful (LTS high), due to their lack of separated pedestrian facilities or sidewalks immediately adjacent to high-speed roadways. Bicycle Level of Traffic Stress A bicycle LTS analysis was conducted to characterize the bicycling experience within the study area. This methodology (MTI 2012) breaks road segments into four classifications for measuring the effects of traffic-based

3-8 October 2020 │ 274-3012-031 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 stress on bicycle riders. The measure of traffic stress quantifies the perceived safety issue of being in close proximity to vehicles, primarily considering the physical distance to traffic and the speed of traffic. For this analysis Ehlen Road, Bents Court, Bents Road, and Dolores Way within the study area were analyzed. In general, Ehlen and Bents Roads have the highest LTS due to the speed of adjacent traffic (greater than 35 mph). 3.3 Future No-Build Conditions This section summarizes the future No-Build transportation conditions in the study area including intersection and freeway traffic operations, crash analysis, and pedestrian and bicycle levels of traffic stress. The 2042 No-Build scenario assumes traffic volumes have continued to grow, but that no changes have been made to the transportation system. This provided a baseline against which alternative solutions were assessed.

3.3.1 2042 Traffic Volumes Volumes for 2042 were forecast by ODOT using a Level 2 TIA-level cumulative analysis methodology consistent with ODOT’s Analysis Procedures Manual (ODOT 2019). Sources of future trip growth through the interchange area included the following: • Anticipated growth in housing and employment in the Cities of Donald and Aurora • Potential land development within the interchange area (consistent with existing comprehensive plans) • Potential expansion of the Aurora State Airport • Regional through-traffic estimated using ODOT’s Statewide Integrated Model The resulting new trips during the 2042 design hour (i.e., the future 30HV) are shown in Figure 3-3 and Figure 3-4. Detailed information regarding the future traffic volume forecasts can be found in 2042 Future Volume Development memorandum in Appendix K, Attachment D.13

3.3.2 Intersection Traffic Operations Intersection traffic operations were analyzed (at all study intersections) using the same tools and methodology applied for existing conditions. As shown in Table 3-4, congestion in the interchange area would increase significantly from existing conditions, with four of the six intersections analyzed failing to meet adopted mobility targets/standards. Both ramp terminals are predicted to have trip demands that are far greater than the available capacity to serve them, indicating significant improvements would be needed. With this level of congestion, the long off-ramp queues that are frequently present today would become much worse, as would the safety hazard created on the freeway mainline. Preliminary traffic signal warrants were again evaluated to determine if signalization of the ramp terminals might be an appropriate solution for relieving congestion and keeping the ramp queues safely away from the freeway mainline. Much like the evaluation for existing conditions, it was found that for the 2042 No-Build condition, preliminary signal warrants would be met for both ramp terminal intersections on Ehlen Road. Preliminary signal warrants were also evaluated for the intersection on Ehlen Road at Dolores Way. The intersection was found to meet one of the two Manual on Uniform Traffic Control Devices criteria for applying signalization, indicating that signalization may be an appropriate solution at some point in the future.

13 I-5: Aurora Donald Interchange (Exit 278) 2042 Future Volume Development, March 26,2019.

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Figure 3-3. 2042 Design Hour Traffic Volumes – All Vehicles

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Figure 3-4. 2042 Design Hour Traffic Volumes – Heavy Trucks Only

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Table 3-4. Future (2042) No-Build Design Hour Traffic Operations at Study Intersections

Performance Intersection Delay Intersection Jurisdiction Control Mobility Target v/c a LOS b (sec/ veh) Ehlen Rd @ Thunderbird Dr Marion County Stop Signs LOS E & 0.47 C 2 v/c < 0.90 Ehlen Rd @ Bents Ct Marion County Stop Signs LOS E & 0.69 D 8 v/c < 0.90 Ehlen Rd @ Flying J driveway Marion County Stop Signs LOS E & 0.76 F 3 v/c < 0.90 Ehlen Rd @ I-5 Southbound ODOT Stop Signs v/c < 0.85 1.79 F 114 ramp terminal/Bents Rd Ehlen Rd @ I-5 Northbound ODOT Stop Signs v/c < 0.85 >2.0 F 107 ramp terminal Ehlen Rd @ Dolores Wy Marion County Stop Signs LOS E & 0.96 F 13 v/c < 0.90 a v/c ratio for worst movement. b LOS for worst movement. Shaded cells indicate adopted mobility standards/ targets are not met.

3.3.3 Freeway Ramp Merge/Diverge Operations Operations analysis was performed for the I-5 freeway mainline in the vicinity of the interchange, including evaluations of congestion on the freeway one mile to the north and south of the interchange, as well as at the points where traffic diverges (exits the freeway) and merges (enters the freeway). Table 3-5 summarizes the results of this analysis for the 2042 No-Build design hour. Locations where freeway congestion is forecast to exceed the mobility target are shown in shaded cells. As shown, all locations are forecast to experience significant congestion by 2042, with all locations failing to meet adopted mobility targets. Congestion in the southbound direction is projected to be much worse than in the northbound direction during the design hour.

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Table 3-5. Future (2042) No-Build Design Hour Traffic Operations on I-5

Mobility Target Performance Location (v/c ratio) (v/c ratio) Southbound I-5 (listed from north to south) Southbound mainline, upstream of the interchange 0.70 1.03 Southbound off-ramp, diverge to Ehlen Rd 0.70 1.03 Southbound mainline, between the on- and off-ramps 0.70 0.90 Southbound on-ramp, merge from Ehlen Rd 0.70 1.04 Southbound mainline, downstream of the interchange 0.70 1.04 Northbound I-5 (listed from south to north) Northbound mainline, upstream of the interchange 0.70 0.89 Northbound off-ramp, diverge to Ehlen Rd 0.70 0.89 Northbound mainline, between the on- and off-ramps 0.70 0.78 Northbound on-ramp, merge from Ehlen Rd 0.70 0.86 Northbound mainline, downstream of the interchange 0.70 0.86

Highway Capacity Software (HCS) 7 software and the HCM 6 methodology were used. Shaded cells indicate adopted mobility targets are not met.

3.3.4 Safety As traffic volumes increase in the future, and the congestion problems become worse as described above, it is anticipated that crashes in the study area would also increase. Areas of concern are the off-ramps, which are projected to be very congested and experience long queues back to the freeway mainline more often than currently experienced. Also, with high levels of congestion projected for the ramp terminal intersections, drivers may attempt to turn onto Ehlen Road into smaller gaps in traffic than they would typically accept. This increased risk-taking in areas with limited sight distance and unexpected conflicts from the five-legged Ehlen Road/Bents Road/I-5 southbound intersection may lead to more crashes.

3.3.5 Pedestrian and Bicycle Travel Conditions The pedestrian and bicycle LTS analyses that were conducted for existing conditions were repeated for the 2042 No-Build conditions to evaluate the quality of facilities for people walking and biking through the interchange area. Since no substantial pedestrian and bicycle improvements are conceived as part of the No-Build, the LTS is unchanged for both pedestrians and cyclists from that of existing conditions.

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4. CONCEPT AND ALTERNATIVES DEVELOPMENT 4.1 Process Overview The process of selecting a preferred design alternative for the Aurora Donald Interchange started in 2016. Figure 4-1 summarizes the overall process of developing a series of concepts, evaluating and refining them into alternatives, then finally selecting the Preferred Alternative. This iterative process allowed for the project team (ODOT and consultants) to explore the strengths and weaknesses of different design approaches to address safety and performance of the interchange. The team applied evaluation criteria to each concept and alternative, eliminating those options with fatal flaws or that performed poorly, while retaining those that performed favorably for further refinement and evaluation. All interchange concepts developed during the process had construction costs that exceeded the available construction funding, meaning that a phased approach to rebuilding the interchange was required. The ability to phase construction was not an evaluation criterion, but was still an important consideration that ODOT reviewed in the advancement of concepts to alternatives and in final selection of the Preferred Alternative. House Bill 2017 (Keep Oregon Moving Act) allocated approximately $25 million to construct the first phase of the Preferred Alternative to improve the interchange. ODOT initiated the preliminary design process by developing over 20 different interchange design concepts intended to address the challenges in and near the interchange. The main challenges associated with the interchange included the following: • Obsolete interchange design • Traffic volumes exceeded capacity at intersections • Safety concerns due to intersection/access spacing • Interchange and adjacent infrastructure not designed to handle the large volume of truck traffic present This brainstorming step included novel interchange concepts that have been successfully implemented elsewhere in the United States. Interchange concepts also included new alignments and intersection treatments for Ehlen and Bents Roads. Other solutions included relocating the interchange elsewhere along I-5. In fall 2016, an internal ODOT project committee, composed of ODOT interchange design specialists and Region 2 planning, traffic, and project delivery staff, conducted a fatal flaw review from the initial pool of over 20 concepts, selecting six concepts for further analysis and design by the consultant team. ODOT selected the following design concepts for further evaluation: • Tight Diamond Interchange • Diamond Interchange with Roundabouts • Single Point Interchange • Diverging Diamond Interchange • Central Roundabout • Folded Diamond

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Figure 4-1. Aurora Donald Interchange Alternatives Selection Process Starting from these six concepts in November 2018, the consultant team saw the need to explore three additional concepts. The three new concepts were variations on the six ODOT-provided design concepts: • Two versions of the Central Roundabout

➢ Central Roundabout with Four Structures – The original concept, which included four structures over I-5.

➢ Central Roundabout with Two Structures – This concept was added as it reduced the number of structures needed across I-5. • Two versions of the Folded Diamond with different intersection treatments

➢ Folded Diamond with Roundabouts

➢ Folded Diamond with Signals • Diamond Interchange with an extended southbound ramp terminal and Roundabouts – This concept was intended to reduce traffic at the Ehlen Road intersection. In early 2019, the ODOT Project Development Team (PDT) met for an intensive workshop with a goal to select three design alternatives from the nine concepts to carry forward for refinement. Facilitated by the consultant

4-2 October 2020 │ 274-3012-031 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 team, representatives from ODOT (representatives from design disciplines, construction, traffic, and the Motor Carrier Division); Marion County Public Works; and the Federal Highway Administration were present to provide diverse insights and input. In addition to selecting design alternatives, this workshop introduced the PDT to the project, discussed existing conditions and issues, and reviewed the project schedule and process. The evaluation framework—outlined in Section 4.2—was applied to each interchange design concept. Each two-dimensional interchange design concept was presented, along with how it performed with respect to the following metrics: • Construction cost • Traffic performance (ratio of traffic volume to roadway capacity [v/c ratio] and intersection delay [LOS]) • Estimated additional right-of-way (ROW) required • Impact on adjacent land uses and businesses Participants discussed the merit of each concept based on their technical expertise and selected the following four concepts for advancement as alternatives: • Single Point Interchange • Diverging Diamond Interchange • Diamond Interchange with Roundabout Ramp Terminals • Central Roundabout with Four Structures These alternatives were advanced for further, three-dimensional design refinement and analysis. After these four were selected for advancement, ODOT Region 2 management reviewed the PDT’s decision and determined that there were serious concerns with the two interchange alternatives that included roundabouts. Traffic analysis indicated that roundabouts would require two lanes to handle future capacity; there is little precedent for two-lane roundabouts in Oregon. Region 2 management noted concerns including a lack of driver familiarity with two-lane roundabouts, as well as substantial freight and farm vehicle use of the interchange. As a result, the Diamond Interchange with Roundabout Ramp Terminals and Central Roundabout with Four Structures alternatives were removed from further consideration. ODOT advanced the single point interchange and diverging diamond interchange for further design and evaluation. ODOT conducted stakeholder and public engagement meetings to get feedback on the alternatives during spring 2019, and then selected the diverging diamond interchange as the Preferred Alternative in June 2019 based on the local government and public feedback and performance relative to the alternative evaluation criteria. 4.2 Concept Evaluation Framework In January 2019 when the PDT met to evaluate nine concepts and select design alternatives for further study, they started with the stated goal of the interchange reconstruction project: “address the safety, operation, and capacity challenges while maintaining efficient movement of passenger and freight traffic through the interchange area.” Based on this goal, the consultant team developed criteria for evaluating the concepts and selecting interchange design alternatives for further study. The criteria are described in detail below.

4.2.1 Construction Cost The overall cost of an improvement is a significant factor in the feasibility of a design concept. Preliminary construction estimates for each design concept were generated using conventional estimating techniques. Each concept’s cost estimate included a 50 percent construction cost contingency to account for design uncertainties.

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The construction costs do not include costs associated with acquiring ROW. Across all alternatives, construction costs range from approximately $30 to $40 million (2019 dollars).

4.2.2 Traffic Performance The traffic performance of each design concept was evaluated based on v/c ratio and LOS at three locations (where applicable): each interchange ramp terminal on Ehlen Road and at the relocated Ehlen Road/Bents Road intersection. This analysis was performed using SIDRA traffic modeling software to estimate future traffic volumes in 2042. OHP and Highway Design Manual (HDM) mobility standards are applicable to the interchange. The OHP mobility target is a v/c ratio of 0.85 at freeway ramp terminals (I-5 mainline mobility target is 0.70); ratios in excess of this result in unacceptable levels of congestion. The ODOT HDM standard for new intersection ramp terminals is a v/c ratio of less than 0.60. Both mobility standards were considered in the transportation performance analysis which considered whether the design concepts and alternatives were forecast to meet or not meet these standards. LOS was also determined for concepts at the relocated Ehlen Road/Bents Road intersection. LOS is a measure of delay drivers experience; categories range from A to F depending on the amount of delay, with A exhibiting the least delay. Both Ehlen Road and Bents Road are owned and operated by Marion County. The County performance standard for the Ehlen Road/Bents Road intersection is LOS D or a v/c ratio of 0.85. The project team analyzed traffic performance for each concept twice: first, with each concept as originally designed, then a second round with modifications intended to improve traffic performance. The improved concepts often involved increasing the roadway vehicle capacity through additional lanes. As a result, v/c ratios improved for almost every design concept, sometimes significantly. See Appendix L for the interchange concept traffic analysis.

4.2.3 Right-of-Way Impacts The concepts were evaluated based on the amount and location of additional ROW that would be needed. The cost associated with acquiring additional ROW was not estimated. The amount of additional ROW was estimated in acres using GIS.

4.2.4 Land Use and Business Impacts The project team evaluated the concepts qualitatively to determine the relative impacts on land use and businesses. The study area encompasses land uses within the ID Zone and agricultural parcels that are zoned EFU. The EFU designation includes specific, robust protections for agricultural land uses. Expanding transportation uses into EFU areas could involve additional land use analysis and permitting. The ID Zone regulates commercial development activities within its bounds. Northwest of the interchange, there is a large undeveloped parcel within the ID Zone that is potentially developable; all concepts would likely affect the developability of this parcel, primarily due to the relocation of Bents Road, and secondarily due to the relocation of Ehlen Road. The interchange design concepts were evaluated based on the estimated ROW impacts to EFU-zoned parcels and developable land within the ID Zone.

4.2.5 Specific Business and Farm Impacts Specific business and farm impacts were evaluated for the RV resort located southeast of the interchange, businesses in the southwest and northwest quadrants (TravelCenters of America Truck Service, Flying J Travel

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Center), and for farmland located in the northeast quadrant of the interchange. The loss of farmland within an EFU-zoned parcel would trigger more involved land use permitting requirements. Many design concepts would involve changes to the RV resort access and loss of farmland east of the interchange. 4.3 Concept Screening This section describes each of the nine interchange concepts and how they performed with respect to the evaluation framework described above. Appendix L provides a summary table comparing impacts and traffic performance of all interchange concepts. Appendix L also includes additional interchange concept comparison information.

4.3.1 TDI – Tight Diamond Interchange

4.3.1.1 Construction Cost: $34 million TDIs (see Figure 4-2) are a common interchange type designed to transition vehicles from a minor road to a limited-access freeway. The freeway itself is grade-separated from the minor road with one crossing the other via a bridge. Freeway travelers access the minor roadway using an off-ramp that diverges only slightly from the travel lane. The off-ramp runs directly across the minor road, becoming an on-ramp that returns to the freeway in similar fashion. The two places where the ramps meet the minor road are treated as conventional intersections with traffic signals. When viewed from above, the on- and off-ramps form a diamond shape. A TDI is used in areas where there is insufficient ROW for a standard diamond interchange. The pair of intersections where the ramps meet the minor road are closely spaced, forcing the minor roadway turn lanes for each direction to run beside each other, requiring a wider road than it would be if it were a standard diamond. This interchange concept included two new I-5 bridges with approximately 300 feet of reconstruction on each end of the I-5 bridges to attain the needed vertical clearance from Ehlen Road. It realigned the Bents Road/Ehlen Road intersection farther to the west to improve sight distances and intersection spacing. In this design concept, traffic flow at the ramp terminals, as well as the Bents Road intersection, was controlled by a traffic signal.

4.3.1.2 Traffic Operations Table 4-1 below summarizes estimated v/c ratios and LOS (as relevant) for the concept as originally designed and the concept after capacity improvements were added. The improved concept added an additional eastbound and westbound travel lane to Ehlen Road and an additional right-turn lane to the southbound off- ramp along with signalizing the southbound off-ramp right turns. The improved concept performed acceptably with respect to LOS at the intersection of Ehlen and Bents Roads, but did not meet OHP mobility or HDM standards for ramp terminal performance.

Table 4-1. TDI Traffic Operation

Concept as Designed Concept with Location (v/c) Improvements (v/c) NB Ramp Terminal 0.89 0.93 SB Ramp Terminal 0.90 0.86 Ehlen Rd/Bents Rd (signal) 0.95 (LOS D) 0.76 (LOS C)

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4.3.1.3 ROW Impacts: 5.7 acres ROW impacts within the southeast quadrant of the interchange would result from modifying the northbound off-ramp, relocating Ehlen Road, and relocating Dolores Way; these changes would require approximately 1.7 acres of ROW. Within the northwest quadrant, relocating both Ehlen and Bents Roads would require approximately 4 acres of ROW.

4.3.1.4 Land Use Impacts This design concept moved Dolores Way outside of the ID Zone boundaries and onto EFU lands. The relocation of Ehlen and Bents Roads would impact development of the vacant parcel in the northwest quadrant of the interchange.

4.3.1.5 Specific Business and Farm Impacts Constructing the TDI interchange would involve significant changes to the RV resort including loss of trailer parking spaces and changes to access and internal circulation. By moving Dolores Way to the east, farmland would be lost within the EFU zone.

Recommendation: Not Preferred

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Figure 4-2. TDI Concept

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4.3.2 Central Roundabout Interchanges These designs included roundabouts at grade-separated interchanges. A roundabout is a type of circular intersection in which road traffic is permitted to flow in one direction around a central island, and priority is typically given to traffic already in the junction. The interchange concepts included a single large single-lane roundabout as the hub of the interchange. The circular roadway of the roundabout would pass under I-5, centered on the I-5 intersection with Ehlen Road. The four freeway ramps and Ehlen Road would intersect the roundabout. The existing Bents Road connection at the southbound ramp terminal would be closed and realigned approximately 800 feet to the west. The relocated Ehlen Road/Bents Road intersection would become a second roundabout. Dolores Way would be realigned and reconnected to Ehlen Road approximately 500 feet east of the existing connection. The two design concepts were variants based on the central roundabout interchange configuration. The number of bridges used by I-5 to pass over the roundabout was the most significant difference between the two designs: CR-2 is a central roundabout interchange with two structures and CR-4 is a central roundabout interchange with four structures.

4.3.2.1 Construction Cost: $39 to 40 million The CR-2 design concept (see Figure 4-3) shifted the existing northbound and southbound alignments of I-5 toward the median. The lane shift would allow both northbound and southbound vehicles to use a single shared structure over Ehlen Road—one structure each over eastbound and westbound Ehlen Road. Unlike CR-2, the CR-4 design concept (see Figure 4-4) did not shift the existing I-5 northbound and southbound alignments to the median. Instead, each direction of travel passes over the roundabout’s circular roadway using four new overcrossing structures—two structures for each direction.

4.3.2.2 Traffic Operations Table 4-2 below summarizes estimated v/c ratios and LOS (as relevant) for both concepts as originally designed and the concepts after capacity improvements were added. The improved concepts added an additional lane to the roundabout and an additional eastbound and westbound approach lane to Ehlen Road. Both improved concepts performed acceptably with respect to LOS at the intersection of Ehlen and Bents Roads. The interchange ramp terminals met OHP mobility standards but did not meet HDM standards for ramp terminal performance.

Table 4-2. CR-2 and CR-4 Traffic Operation

Concept as Concept with Location Designed (v/c) Improvements (v/c) Ramp Terminals 1.39 0.81 Ehlen Rd/Bents Rd 1.36 (LOS F) 0.79 (LOS C) (roundabout)

4.3.2.3 ROW Impacts: 5.7 acres Estimated ROW impacts for both concepts were similar. Changes within the southeast quadrant of the interchange included modifying the northbound off-ramp, relocating Ehlen Road, and relocating Dolores Way;

4-8 October 2020 │ 274-3012-031 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 these changes would require approximately 1.9 acres of ROW. In the northwest quadrant, relocating both Ehlen and Bents Roads would require approximately 3.8 acres of ROW.

4.3.2.4 Land Use Impacts CR-2 and CR-4 moved Dolores Way outside of the current ID Zone boundaries and onto EFU lands. The relocation of Ehlen and Bents Roads would impact development of the vacant parcel in the northwest quadrant of the interchange.

4.3.2.5 Specific Business and Farm Impacts The CR-2 or CR-4 interchange included relocating the RV resort access, resulting in changes to the internal circulation. By moving Dolores Way to the east, farmland would be lost within the EFU zone.

Recommendation: Advance CR-4 as Alternative

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Figure 4-3. CR-2 Concept

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Figure 4-4. CR-4 Concept

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4.3.3 DIR – Diamond Interchange with Roundabout Ramp Terminals

4.3.3.1 Construction Cost: $34 million This design concept (see Figure 4-5) featured freeway ramps that form a diamond shape when viewed from above. Unlike the TDI design concept, the DIR concept included a twin set of single-lane roundabouts at the ramp terminals for each direction of travel on I-5. The two roundabouts were interconnected and would function in conjunction. Unlike traditional roundabouts with a circular central island, the dual teardrop-shaped roundabouts require a complete lap of the two roundabouts to execute a U-turn. When viewed from above, this configuration of linked roundabouts is known as a “dog bone”—two round ends connected by a narrower roadway. This interchange concept included a teardrop roundabout at both the northbound and southbound ramp terminals. Bents Road was realigned with Bents Court with a third roundabout. The existing Bents Road connection at the southbound ramp terminal was closed and both I-5 bridges replaced. The Ehlen Road alignment was shifted to the north on the west side of the interchange. Dolores Way access was relocated to the east, and the existing access was converted to a cul-de-sac.

4.3.3.2 Traffic Operations Table 4-3 below summarizes estimated v/c ratios and LOS (as relevant) for the concept as originally designed and the concept after capacity improvements were added. The improved concept added an additional lane to the roundabout and an additional eastbound and westbound approach lane to Ehlen Road. The improved concept performed acceptably with respect to LOS at the intersection of Ehlen and Bents Roads. Both interchange ramp terminals met OHP mobility standards. The southbound interchange ramp terminal met HDM standards, but the northbound ramp terminal did not meet the HDM standard for ramp terminal performance.

Table 4-3. DIR Traffic Operation

Concept as Concept with Location Designed (v/c) Improvements (v/c) NB Ramp Terminal 1.78 0.79 SB Ramp Terminal 0.96 0.59 Ehlen Rd/Bents Rd 1.36 (LOS F) 0.79 (LOS C) (roundabout)

4.3.3.3 ROW Impacts: 5.9 acres ROW impacts within the southeast quadrant of the interchange included modifying the northbound off-ramp, relocating Ehlen Road, and relocating Dolores Way; these changes required approximately 1.9 acres of ROW. Within the northwest quadrant, relocating both Ehlen and Bents Roads required approximately 4 acres of ROW.

4.3.3.4 Land Use Impacts This design concept moved Dolores Way outside of the current ID Zone boundaries and onto EFU lands. The relocation of Ehlen and Bents Roads impacted development of the vacant parcel in the northwest quadrant of the interchange.

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4.3.3.5 Specific Business and Farm Impacts Constructing the DIR interchange involved significant changes to the RV resort including loss of trailer parking spaces and changes to access and internal circulation. By moving Dolores Way to the east, farmland would be lost within the EFU zone.

Recommendation: Advance as Alternative

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Figure 4-5. DIR Concept

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4.3.4 FDR – Folded Diamond Interchange with Roundabout Ramp Terminals

4.3.4.1 Construction Cost: $31 million This design concept (see Figure 4-6) was a hybrid that combined elements of a few interchange styles: cloverleaf and diamond with single-lane roundabouts at the ramp terminals. For this design, the northbound off-ramp was “folded” into the northeast quadrant of the interchange and tucked into the space between the interstate and northbound on-ramp. With a folded diamond ramp configuration, entrance and exit ramps terminate on the same side of the surface street. This interchange concept included roundabout ramp terminals, with the northbound terminal aligned with Dolores Way. The northbound off-ramp was a folded ramp design that curves around within the extent of the northbound on-ramp. The southbound ramp terminal roundabout was a teardrop design, while the northbound ramp terminal was a traditional circular roundabout. Bents Road was realigned with Bents Court at Ehlen Road with a circular roundabout. The existing Bents Road connection at the southbound ramp terminal was closed. In this design concept, both northbound and southbound I-5 bridges were replaced; the northbound bridge was slightly wider to accommodate the off-ramp and related gore area. Ehlen Road was shifted to the north on the west side of the interchange.

4.3.4.2 Traffic Operations Table 4-4 below summarizes estimated v/c ratios and LOS (as relevant) for the concept as originally designed and the concept after capacity improvements were added. The improved concept added an additional lane to the roundabout, an additional eastbound and westbound approach lane to Ehlen Road, and an additional entry lane to the northbound off-ramp. The improved concept performed acceptably with respect to LOS at the intersection of Ehlen and Bents Roads. The interchange ramp terminals met OHP mobility standards but did not meet HDM standards for ramp terminal performance.

Table 4-4. FDR Traffic Operation

Concept as Concept with Location Designed (v/c) Improvements (v/c) NB Ramp Terminal 1.34 0.78 SB Ramp Terminal 1.16 0.75 Ehlen Rd/Bents Rd 1.36 (LOS F) 0.79 (LOS C) (roundabout)

4.3.4.3 ROW Impacts: 9 acres In the northeast quadrant, constructing the folded ramp required approximately 5 acres of ROW. Relocating Ehlen Road and Bents Road—in the northwest quadrant of the interchange—required approximately 4 acres of ROW.

4.3.4.4 Land Use Impacts The folded ramp configuration in the northeast quadrant of the interchange required ROW outside of the current ID Zone boundaries and would be constructed on EFU lands. The relocation of Ehlen and Bents Roads impacted development of the vacant parcel in the northwest quadrant of the interchange.

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4.3.4.5 Specific Business and Farm Impacts Constructing the FDR interchange involved a loss of farmland within EFU zoning due to the folded ramp configuration in the northeast quadrant of the interchange.

Recommendation: Not Preferred

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Figure 4-6. FDR Concept

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4.3.5 FDS – Folded Diamond Interchange with Signalized Ramp Terminals

4.3.5.1 Construction Cost: $35 million This design concept (see Figure 4-7) is functionally identical to the FDR design concept, apart from some key features. Most notably, the ramp terminal roundabouts in the FDR configuration were replaced with four-way, traffic signal–controlled intersections. The northbound ramp terminal was aligned with Dolores Way. Ehlen Road, between the northbound and southbound ramp terminals, was made wider to accommodate dual left- turn lanes at both on-ramps. To accommodate this wider roadway, both I-5 bridges were replaced with longer spans. The northbound bridge was widened to accommodate the off-ramp. Like the FDR design, the northbound off-ramp was a folded ramp design “tucked” within the on-ramp for the same direction. Ehlen Road was realigned to the north on the west side of the interchange. Bents Road was realigned with Bents Court at Ehlen Road at a circular roundabout. The existing Bents Road connection at the southbound ramp terminal was closed.

4.3.5.2 Traffic Operations Table 4-5 below summarizes estimated v/c ratios and LOS (as relevant) for the concept as originally designed and for the concept after capacity improvements were added. The improved concept added an additional eastbound and westbound travel lane and dual northbound and southbound left-turn lanes to Ehlen Road. The improved concept performed acceptably with respect to LOS at the intersection of Ehlen and Bents Roads, but did not meet ODOT OHP or HDM standards for ramp terminal performance.

Table 4-5. FDS Traffic Operation

Concept as Concept with Location Designed (v/c) Improvements (v/c) NB Ramp Terminal 1.55 0.88 SB Ramp Terminal 1.03 0.90 Ehlen Rd/Bents Rd 1.36 (LOS F) 0.79 (LOS C) (roundabout)

4.3.5.3 ROW Impacts: 9.2 acres Within the southeast quadrant of the interchange, changes to Ehlen Road would require 0.2 acre of ROW. In the northeast quadrant, the folded ramp would require approximately 5 acres of ROW. Relocating Ehlen Road and Bents Road—in the northwest quadrant of the interchange—would require approximately 4 acres of ROW.

4.3.5.4 Land Use Impacts The folded ramp configuration in the northeast quadrant of the interchange would require ROW outside of the current ID Zone boundaries and would be developed on EFU lands. Relocating Ehlen and Bents Roads would impact development of the vacant parcel in the northwest quadrant of the interchange.

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4.3.5.5 Business and Farm Impacts Constructing the FDS interchange would include loss of farmland within EFU zoning due to the folded ramp configuration in the northeast quadrant of the interchange. This design concept would include minor property impacts to the RV resort.

Recommendation: Not Preferred

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Figure 4-7. FDS Concept

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4.3.6 DGR – Diamond Interchange with Gullwing West and Roundabout Ramp Terminals

4.3.6.1 Construction Cost: $37 million Like the FDR design concept, the DGR interchange design configuration combined elements from other designs. A distinct part of this concept (see Figure 4-8) was the unique configuration of the southbound ramps which were significantly extended to the west to terminate at a traditional circular roundabout with Bents Road. The closed and realigned Bents Road connected southbound freeway traffic to Ehlen Road at a signalized intersection at Bents Court. The southbound on-ramp used a fly-over bridge to reduce conflicts with Ehlen Road. In this configuration, the northbound ramp terminals were connected to a teardrop roundabout at Ehlen Road. The connection between the northbound and southbound roundabout ramp terminals—one circular and the other teardrop—was controlled by a traffic signal at Ehlen Road and Bents Road/Court. Three bridges were required in this design concept to span Ehlen Road: the new southbound on-ramp fly-over, and the replaced northbound and southbound I-5 bridges. Dolores Way was closed and would be realigned to intersect with an Ehlen Road farther to the east at a T intersection.

4.3.6.2 Traffic Operations Table 4-6 below summarizes estimated v/c ratios and LOS (as relevant) for the concept as originally designed and the concept after capacity improvements were added. The improved concept added an additional lane to the northbound off-ramp terminal roundabout and an additional eastbound and westbound approach lane to Ehlen Road. The improved concept performed acceptably with respect to LOS at the intersection of Ehlen and Bents Roads. The northbound interchange ramp terminal met OHP mobility standards, but the southbound ramp terminal did not. Both interchange ramp terminals did not meet HDM standards for ramp terminal performance.

Table 4-6. DGR Traffic Operation

Concept as Concept with Location Designed (v/c) Improvements (v/c) NB Ramp Terminal 1.66 0.79 SB Ramp Terminal 1.17 0.87 Ehlen Rd/Bents Rd >2.0 (LOS F) 0.86 (LOS C) (roundabout)

4.3.6.3 ROW Impacts: 6.2 acres Within the southeast quadrant, changes to Ehlen Road and the northbound off-ramp, and the relocation of Dolores Way required approximately 1.9 acres of ROW. The gullwing configuration of the southbound ramps and realignment of Bents Road—in the northwest quadrant of the interchange—required approximately 4.3 acres of ROW.

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4.3.6.4 Land Use Impacts The relocation of Ehlen and Bents Roads impacted development of the vacant parcel in the northwest quadrant of the interchange. The relocation of the Ehlen Road/Dolores Way intersection in the southeast quadrant resulted in a loss of EFU land.

4.3.6.5 Specific Business and Farm Impacts Constructing the DGR interchange involved a loss of developable land within the ID Zone due to constructing the gullwing ramp. Relocating Dolores Way east of the interchange resulted in a loss of EFU farmland. This design concept involved significant changes to the RV resort including loss of trailer parking spaces and changes to access and internal circulation.

Recommendation: Not Preferred

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Figure 4-8. DGR Concept

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4.3.7 SPI – Single Point Interchange 4.3.7.1 Construction Cost: $38 million An SPI interchange features a large overpass that provides space for one traffic signal–controlled intersection for the minor road and left-turning movements onto or off of the interchange. The SPI design is used where there are large volumes of traffic and restricted ROW available. Ramp entrances/exits converge on a single intersection. It is a variant of a diamond interchange; however, all four turning movements intersect at a common point. Opposing streams of left-turning traffic do not cross and turns can be made at the same time. The single traffic signal enables more vehicles to turn and clear the interchange during a single traffic signal cycle. The long, gradual turns of an SPI interchange enable easier navigation for larger vehicles such as trucks, buses, and recreational vehicles. This interchange design concept (see Figure 4-9) featured a single large bridge that elevated I-5 over Ehlen Road. Accomplishing this objective required raising the grade of I-5 to attain vertical height clearance for the single intersection below. To minimize the impacts of the ramps, the northbound and southbound directions of I-5 needed to be realigned and brought closer together in the current median. The SPI concept involved realigning Bents Road and Ehlen Road to improve sight distances and intersection spacing. 4.3.7.2 Traffic Operations Table 4-7 below summarizes estimated v/c ratios and LOS (as relevant) for the concept as originally designed and the concept after capacity improvements were added. The improved concept added an additional southbound left-turn lane and an additional eastbound through lane to Ehlen Road. The SPI concept (with improvements) would meet ODOT OHP v/c standards and would come close to meeting HDM standards at the ramp terminals, as well as would have an acceptable LOS at the Ehlen Road/Bents Road intersection.

Table 4-7. SPI Traffic Operation

Concept as Designed Concept with Location (v/c) Improvements (v/c) Ramp Terminals 0.80 0.63 Ehlen Rd/Bents Rd 0.95 (LOS D) 0.76 (LOS C) (signal)

4.3.7.3 ROW Impacts: 4.3 acres Within the southeast quadrant, changes to the northbound off-ramp required approximately 0.3 acre of ROW. Meanwhile in the northwest quadrant of the interchange, the relocation of Ehlen Road and Bents Road required approximately 4 acres of ROW. 4.3.7.4 Land Use Impacts The relocation of Ehlen and Bents Roads impacted development of the vacant parcel in the northwest quadrant of the interchange. 4.3.7.5 Business and Farm Impacts No significant impacts are expected. Recommendation: Advance as Alternative

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Figure 4-9. SPI Concept

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4.3.8 DDI – Diverging Diamond Interchange

4.3.8.1 Construction Cost: $39 million A DDI is also called a double crossover diamond interchange. In this configuration, traffic on the minor road crosses to the opposite side of the road while within the interchange. Dual traffic signals control the movement of traffic during this crossover maneuver. Upon reaching the second traffic signal, vehicles are returned to driving on the right side of the road. This orientation allows all signalized intersections in the interchange to operate with two-phase operation. These interchanges also improve safety, because there are no left turns across opposing traffic, and most turning movements are controlled by signals. Another benefit is that left and right turns can occur simultaneously. The DDI design concept (see Figure 4-10) involved two new I-5 bridges to carry traffic over Ehlen Road. This required reconstruction of the I-5 travel lanes to attain vertical clearance. Realignment of Ehlen Road westbound was required to create approach angles for the crossover intersections. Bents Road and Dolores Way were realigned to improve sight distances and intersection spacing, while allowing full access to the adjacent businesses.

4.3.8.2 Traffic Operations Table 4-8 below summarizes estimated v/c ratios and LOS (as relevant) for the concept as originally designed There were no modifications required to this interchange design concept to attain an acceptable v/c ratio. The DDI concept is the only concept that would meet both ODOT HDM and OHP v/c standards at the ramp terminals, as well as have an acceptable LOS at the Ehlen Road/Bents Road intersection.

Table 4-8. DDI Traffic Operation

Concept as Designed Concept with Location (v/c) Improvements (v/c) NB Ramp Terminal 0.46 N/A SB Ramp Terminal 0.57 N/A Ehlen Rd/Bents Rd 0.95 (LOS D) N/A (signal)

4.3.8.3 ROW Impacts: 7.1 acres Within the southeast quadrant of the interchange, changes to Ehlen Road and the northbound off-ramp, and the relocation of Dolores Way required approximately 1.7 acres of ROW. In the northwest quadrant, the realignment of Bents Road and Ehlen Road required approximately 5 acres of ROW. On the northeast quadrant, alignment shifts for Ehlen Road required approximately 0.4 acre.

4.3.8.4 Land Use Impacts The relocation of Ehlen and Bents Roads impacted development of the vacant parcel in the northwest quadrant of the interchange. The relocation of Ehlen Road to the north and the Dolores Way intersection in the southeast quadrant resulted in a loss of EFU-zoned land.

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4.3.8.5 Specific Business and Farm Impacts Constructing the DDI interchange involved a loss of farmland within EFU zoning due to shifting Ehlen Road to the north and relocating Dolores Way to the east. This design concept involved significant changes to the RV Resort including loss of trailer parking spaces and changes to access and internal circulation.

Recommendation: Advance as Alternative

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Figure 4-10. DDI Concept

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4.4 Selecting the Preferred Alternative Based on the concept evaluation above, the following interchange concepts were advanced as alternatives: • Single Point Interchange (SPI) • Diverging Diamond Interchange (DDI) • Diamond Interchange with Roundabout Ramp Terminals (DIR) • Central Roundabout Interchange with Four Structures (CR-4) The DIR and CR alternatives were subsequently removed from consideration; ODOT Region 2 management determined that there were serious concerns with the two interchange alternatives that included roundabouts. Traffic analysis indicated that roundabouts would require two lanes to handle future capacity; there is little precedent for two-lane roundabouts in Oregon. Region 2 management noted concerns including a lack of driver familiarity with two-lane roundabouts, substantial truck traffic volumes, and farm vehicle traffic using the interchange. This left two alternatives for further consideration: the SPI and DDI. The SPI and DDI alternatives were both refined by the consultant team.

4.4.1 Refinement of Alternatives Both the SPI and DDI alternatives were developed to higher levels of engineering design to refine impacts, costs, and transportation performance. More detailed bridge and roadway design elements such as bridge span lengths, retaining walls, ramp and road profile were developed. Additional traffic analyses were performed for the SPI and DDI alternatives (see Appendix L). Specific refinements to each alternative are noted below. Refinements to the SPI alternative included the following: • Moved the northbound exit ramp farther away from I-5 to allow for a flatter crossing angle under the bridge. This allows a flatter slope, but also increases the distance between stop bars on Ehlen Road. • Shortened the bridge span as a result of the revision noted above. The flatter crossing angle improves sight distance. • Evaluated the following bridge alternatives:

➢ Single-span steel girder

➢ Three-span steel girder

➢ Three-span bulb-T girder • Added dual right-turn lanes to the northbound Bents Court/eastbound Ehlen Road movement to improve traffic performance. In order to avoid significant impacts to the Flying J, the Bents Road/Bents Court alignment was shifted to the west. • Added dual left-turn lanes to the southbound Bents Road/eastbound Ehlen Road movement to improve traffic performance. • Added dual left-turn lanes to the westbound Ehlen Road/southbound Bents Court movement to improve traffic performance. This requires an additional receiving lane on southbound Bents Road. • Traffic analysis – The refinements result in an SPI ramp terminal v/c ratio of 0.81 The SPI meets OHP mobility targets but does not meet HDM standards. Refinements to the DDI included the following:

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• Examined different median widths to provide the best crossing angles of the crossover intersections on Ehlen Road. • Added dual right-turn lanes to the northbound Bents Court/eastbound Ehlen Road movement to improve traffic performance. In order to avoid significant impacts to the Flying J, the Bents Road/Bents Court alignment was shifted to the west. • Added dual left-turn lanes to the southbound Bents Road/eastbound Ehlen Road movement to improve traffic performance. • Added dual left-turn lanes to the westbound Ehlen Road/southbound Bents Court movement to improve traffic performance. This requires an additional receiving lane on southbound Bents Road. • Traffic analysis – The refinements result in a northbound ramp terminal v/c ratio of 0.29 and a southbound ramp terminal v/c ratio of 0.35; both meet OHP and HDM standards. The following figures show the refined alternatives and their respective cross sections.

Figure 4-11. SPI Concept Alternative

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Figure 4-12. SPI Concept Cross Sections

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Figure 4-13. DDI Concept Alternative

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Figure 4-14. DDI Concept Cross Sections The consultant team created an evaluation matrix to understand the relative pros and cons of each alternative. Table 4-9 shows the criteria the consultant team developed to evaluate how each alternative performed relative to the other alternative. The criteria are based on the project problem statement, goals, and objectives described in Chapter 1. If the DDI or SPI performed better, the reason is listed next to the criterion. The table also shows where there was no significant difference between the alternatives. Considering all criteria, the DDI alternative performed better than the SPI.

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Table 4-9. Alternative Evaluation

Criterion Better Performer Why? Construction cost DDI SPI has 16% greater cost than DDI ROW impacts No Significant Difference N/A Utility impacts No Significant Difference N/A Maintenance (long-term) DDI Less long-term maintenance Traffic operations DDI Better operations, except max. queue length Bike/ped safety DDI Easier crossing of Ehlen Road at the interchange Freight mobility No Significant Difference N/A Safety for all users DDI Crash reduction; safety for vulnerable users Accessibility No Significant Difference N/A Construction staging SPI Fewer construction impacts Feasibility (Phase 1) No Significant Difference N/A Historic resource impacts No Significant Difference N/A Archaeological resource impacts No Significant Difference N/A Hazmat DDI TCA water quality pond relocation Noise impacts No Significant Difference N/A Environmental justice No Significant Difference N/A Land use No Significant Difference N/A Geotechnical No Significant Difference N/A Drainage design No Significant Difference N/A Roadway design No Significant Difference N/A Bridge design DDI Two-span bridge Wall design No Significant Difference N/A Traffic design No Significant Difference One complex signal vs. two simple signals Impacts to I-5 DDI Less change to roadway profile Impacts to Ehlen Rd DDI Less Ehlen Road widening Impacts to other local roads No Significant Difference N/A Public familiarity with design SPI Other interchanges in Oregon and Washington Risk No Significant Difference N/A Public acceptance No Significant Difference N/A Incident response time DDI Easier to detour traffic through interchange

4.4.2 Preferred Alternative In May 2019, the PDT met to review the SPI and DDI alternatives. The meeting resulted in a unanimous recommendation to select the DDI as the Preferred Alternative. Region 2 management agreed with the PDT recommendation and directed the project team to present the DDI alternative to stakeholders and the public as ODOT’s recommended alternative.

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5. PREFERRED ALTERNATIVE This chapter describes the Preferred Alternative for the Aurora Donald Interchange. Figure 5-1 illustrates the overall process for refining the Preferred Alternative design elements and selecting the best project phasing plan. The following sections provide an overview of the refinement process, project phasing options, access management, and land use requirements. This chapter also includes findings from traffic analysis performed by ODOT and the project team. See Appendix M for additional information on the Preferred Alternative.

Figure 5-1. Preferred Alternative Refinement and Phasing

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5.1 The Diverging Diamond Interchange ODOT selected a DDI as the Preferred Alternative for the Aurora Donald Interchange Project (Figure 5-2) after A DDI is also called a double crossover developing and evaluating a number of different interchange diamond interchange. In this concepts and alternatives. configuration, traffic on the minor The Preferred Alternative would construct two new I-5 road crosses to the opposite side of bridges to carry east-west traffic over Ehlen Road. The two the road while within the interchange. new I-5 bridges would require reconstruction of the I-5 travel Dual traffic signals control the lanes to attain additional vertical clearance over Ehlen Road. movement of traffic during this Realignment of Ehlen Road east and west of I-5 would also be crossover maneuver. Upon reaching required to create the desired approach angles for the crossover intersections. Bents Road and Dolores Way would the second traffic signal, vehicles are both be relocated to improve sight distances and intersection returned to driving on the right side of spacing, while allowing full access to the adjacent businesses. the road. This orientation allows all signalized intersections in the The Preferred Alternative consists of the following elements: interchange to operate with • Construction of a new DDI with new signalized two-phase operation. These intersections located at the northbound and interchanges improve safety because southbound ramp terminals at Ehlen Road. there are no left turns across opposing • A realigned Ehlen Road with a wider cross section traffic and most turning movements under I-5; the wider road would include two lanes in are controlled by signals. Another each direction and bike and pedestrian facilities. safety and traffic operation benefit is • Reconstruction and widening of the existing I-5 that left and right turns can occur northbound and southbound bridges to simultaneously. accommodate the wider Ehlen Road cross section and larger bridge support beams. • Realignment of Bents Road to align with Bents Court at Ehlen Road, and other improvements to Bents Court at Ehlen Road. • Realignment of Dolores Way to create a new intersection farther east with Ehlen Road. • Northbound on- and off-ramp lengthening and widening. • Southbound on- and off-ramp lengthening and widening. • Improvements to stormwater drainage and management.

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Figure 5-2. Preferred Alternative – June 2019

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5.2 Preferred Alternative Refinement

5.2.1 Value Engineering (VE) Process All ODOT highway construction projects in the Statewide Transportation Improvement Program must be screened based upon established criteria to determine the need to conduct a formal VE study. ODOT Policy No. DES 05-01 states that all projects with an estimated cost of $50 million or more are required to have a VE study regardless of funding source or National Highway System designation. Prior to the VE study, the estimated construction cost of the Preferred Alternative was approximately $70 million, exclusive of project engineering and ROW costs. Therefore, the need for a VE study was triggered with the following objectives in mind: • Improve the project’s overall value • Reduce risk • Identify phasing options that align with existing funding from the Keep Oregon Moving Act During the VE study, analytical tools and techniques were applied to develop a better understanding of the Preferred Alternative. A major component of this analysis was determining Value Metrics which assess the elements of cost, performance, time, and risk as they relate to project value. These elements required a deeper level of analysis, the VE results of which are detailed in Appendix M. The VE team developed 20 design concepts to improve the project; 10 were recommended to the project team to incorporate into interchange engineering design to reduce cost, improve performance, and reduce risk. The recommendations were incorporated into the DDI interchange design, resulting in a refined Preferred Alternative that is described and analyzed further in the next section. 5.3 Preferred Alternative The refined Preferred Alternative (see Figure 5-3) would construct one new I-5 bridge to carry north- and southbound traffic over Ehlen Road. The new I-5 bridge would require reconstruction of the I-5 travel lanes to attain additional vertical clearance over Ehlen Road and would move the I-5 southbound lanes east, into the median to align with the new bridge structure. Realignment of Ehlen Road west of I-5 would also be required to create the desired approach angles for the crossover intersections. Bents Road and Dolores Way would both be realigned to improve sight distances and intersection spacing, while allowing full access to the adjacent businesses. Figure 5-3 shows the refined Preferred Alternative, and Figure 5-4 shows a cross section of the I-5 bridge over Ehlen Road.

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Figure 5-3. Refined Preferred Alternative

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Figure 5-4. Refined Preferred Alternative Cross Section

The refined Preferred Alternative consists of the following elements: • Construction of a new DDI with new signalized intersections located at the northbound and southbound ramp terminals at Ehlen Road. • Construction of one new I-5 bridge to carry both north- and southbound traffic over Ehlen Road. • Reconstruction of the I-5 travel lanes to match the new I-5 bridge. • Realignment of I-5 southbound lanes east, into the median, to align with the new bridge structure. • Northbound on- and off-ramp lengthening and widening improvements. • Southbound on- and off-ramp lengthening and widening improvements. • A wider, realigned Ehlen Road with a wider cross section under I-5 to include two lanes in each direction with bike and pedestrian facilities. • Realignment of Bents Road to align with Bents Court at existing Ehlen Road. • Realignment of Ehlen Road, west of I-5, to the north and a new Ehlen Road/Bents Road intersection. • Realignment of Dolores Way to create a new intersection farther east with Ehlen Road. The estimated construction cost is $72 million. The Preferred Alternative cost estimate is included in Appendix N.

5.3.1 Right-of-Way The anticipated ROW needed for the Preferred Alternative is a about 21.3 acres. Within the southeast quadrant of the interchange, changes to Ehlen Road and the northbound off-ramp and the relocation of Dolores Way would require approximately 3.4 acres. In the northeast quadrant of the interchange,

5-6 October 2020 │ 274-3012-031 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 changes to Ehlen Road would require about 3.5 acres. In the northwest quadrant, the realignment of Bents Road and Ehlen Road would require approximately 14.4 acres.

5.3.2 Transportation Performance Table 5-1 summarizes transportation performance of the Preferred Alternative for the 2042 design year. All intersections would perform acceptably and would meet mobility targets, with the ramp intersections having reserve capacity for the future. The Preferred Alternative traffic analysis report is included in Appendix M.

Table 5-1. Preferred Alternative 2042 Performance

Preferred Mobility Target Alternative 2042 Location v/c, LOS v/c, LOS NB Ramp/Ehlen Rd 0.85, N/A 0.27, N/A SB Ramp/Ehlen Rd 0.85, N/A 0.34, N/A New Ehlen Rd/Bents Rd 0.85, LOS D 0.57, LOS D Old Ehlen Rd/Bents Ct 0.90, LOS E 0.30, LOS C New Dolores Way/Ehlen Rd 0.85, LOS D 0.78, LOS B

The Preferred Alternative would maintain mobility at both ramp intersections well below the required 0.85 v/c mobility target. ODOT intends to preserve capacity at this interchange by adopting alternative mobility targets (AMTs) that are lower than the current OHP mobility targets. In this instance, where a State/ODOT improvement provides more capacity than will be needed to serve the existing adopted land uses in Marion County’s Comprehensive Plan, lowering the v/c-based AMTs will help preserve the additional capacity for the next increment of growth beyond the 20-year planning horizon. ODOT will establish an AMT of 0.6 v/c for both ramp intersections. These AMTs will be adopted by the Oregon Transportation Commission (OTC) as part of the IAMP and will replace existing mobility targets when the Preferred Alternative is constructed. The AMTs will also meet the mobility standard for ramp intersections in the HDM, therefore avoiding the need for a mobility-related design exception as part of the final design process.

5.3.3 Environmental Impacts The Preferred Alternative would have impacts to the built and natural environments, but for a project of its size and scale, the impacts are relatively minor. ODOT and the Federal Highway Administration completed federal environmental documentation to support a categorical exclusion because the project’s individual and cumulative impacts are not significant on the natural and built environments. Below is a brief description of impacts to the natural and built environments. The approved categorical exclusion is included in Appendix O.

5.3.3.1 Natural Environment • Wetlands – Small pockets of wetland vegetation are present within the project area and would be impacted by the project. Mitigation for lost wetlands would be required.

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• Stormwater – Increases in impervious surface and changes in drainage patterns would trigger stormwater management requirements. Stormwater from the project area discharges to several small unnamed tributaries of Senecal Creek. Stormwater treatment and detention (flow control) would be required for the project. • Endangered Species Act (ESA) – No critical habitats or ESA-listed fish, animal, or plant species are present within the project area. The project would remove some riparian vegetation adjacent to a non-fish-bearing stream. Mitigation for lost riparian vegetation would be required.

5.3.3.2 Built Environment • Historic Resources – Several BPA towers are present within the project area. The towers and lines are part of the Big Eddy-Chemawa No. 1 line (Historically Oregon City-Chemawa No. 3). This line was constructed in 1955. The transmission line in the project area meets the criteria for eligibility for listing in the NRHP. No adverse impacts to the towers are anticipated. No other historic resources are present in the project area. • Cultural Resources – Two locations of historic debris scatter and/or farmstead features were identified during the archaeological survey and are recommended for further evaluation for their potential for listing in the NRHP. Section 4(f) applies to archaeological sites that are on or eligible for the NRHP and that warrant preservation in place, including those sites discovered during construction; thus, if this archaeological site is eligible for listing and is important to be left in place, a Section 4(f) evaluation could be necessary. No other cultural resources are present in the project area. • Parks – A privately owned grassy open space is present and would be impacted by the project, but it is not protected by Section 4(f) due to private ownership. There are no public recreation resources present in the project area. • Socioeconomic – The project would benefit the traveling public and area businesses by improving safety and relieving congestion at the interchange and along Ehlen Road. A low-income population may be present at the Aurora Acres RV Park, located in the southeast quadrant of the interchange. A majority of the occupants of the Aurora Acres RV Park are permanent residents. Sound abatement is being considered to reduce freeway-generated noise at the RV park. • Air Quality – The project area is in attainment for all air quality requirements. No air quality analysis is required. • Noise – A noise analysis determined that a sound wall adjacent to the Aurora Acres RV Park along the northbound off-ramp is cost-effective and would benefit RV park residents. A sound wall would be considered during final design if found to be reasonable and feasible. • Hazardous Materials – The project is in close proximity to three gas stations and two truck stops and could require hazardous material mitigation. 5.4 Phase 1 Phasing of the Preferred Alternative is needed to accommodate the initial $25 million in funding allocated by the state legislature from the Keep Oregon Moving Act. This amount represents a

5-8 October 2020 │ 274-3012-031 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 substantial down payment toward implementing the Preferred Alternative, but would not cover the full estimated cost of $71.5 million. As a result, the project team developed an initial Phase 1 project. For Phase 1 to be effective, the improvements must address the most significant safety and mobility issues for several years into the future. No funding to complete the interchange improvements has been identified, and it could be more than 10 years from IAMP adoption before the additional funding is allocated. The most significant safety issues experienced today include long vehicle queues on the I-5 exit ramps spilling back to the freeway mainline (especially on the southbound ramp), turning conflicts around the closely spaced intersections on Ehlen Road with Bents Road and the I-5 southbound exit ramp, and limited sight distance associated with the narrow underpass. The project team developed and analyzed two different alternatives for Phase 1. The difference between the alternatives was whether or not the existing I-5 bridges would be replaced. For each of these Phase 1 alternatives, the team developed multiple design options, refined them through design review and traffic analysis results, resulting in two main alternatives for Phase 1 (known as Phase 1A and Phase 1B). The 1B Alternative significantly outperformed 1A and was selected as the preferred Phase 1 Alternative. See Appendix M for more details on Phase 1 alternatives development. The Phase 1 project consists of the following elements (see Figure 5-5): • Construction of one new I-5 bridge to carry both north- and southbound traffic over Ehlen Road. • Reconstruction of the I-5 travel lanes to match the new I-5 bridge. • Realignment of I-5 southbound lanes east, into the median to align with the new bridge structure. • Lengthen, widen, and signalize northbound and southbound off-ramps. • Construction of a four-lane cross section on Ehlen Road, between the northbound and southbound I-5 ramps, with left-turn lanes to access the I-5 on-ramps and one through lane in each direction. • Realignment of Bents Road to align with Bents Court at existing Ehlen Road. Figure 5-5 shows the Phase 1 project and Figure 5-6 shows a cross section of the I-5 bridge over Ehlen Road with the travel lane configuration. The estimated cost for Phase 1 is $50 million (construction, engineering, and ROW). The Phase 1 cost estimate is included in Appendix P.

5.4.1 Right-of-Way The anticipated ROW needed for Phase 1 is a about 7.1 acres in the northwest quadrant of the interchange for relocating Bents Road and widening Ehlen Road. It is anticipated that temporary construction easements would be needed along the south side of Ehlen Road between the southbound on-ramp and Bents Court (along the Flying J Truck Stop frontage) and along the southbound off-ramp west of I-5. East of I-5, it is anticipated that temporary construction easements would be needed along the northbound off-ramp and the south side of Ehlen Road for the noise/retaining wall and on the north side of Ehlen Road. No ROW is needed for Phase 1 on the east side of I-5.

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Figure 5-5. Phase 1 Improvements

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Figure 5-6. Phase 1 Alternative Cross Section

5.4.2 Transportation Performance

5.4.2.1 Phase 1 Table 5-2 below summarizes transportation performance of Phase 1. The table shows the estimated v/c ratios for Phase 1 ramp intersections and the estimated v/c ratios and LOS for the Ehlen Road/Bents Road/Bents Court intersection in 2022, 2030, and 2042 design years. The northbound ramp intersection would fail to meet the OHP mobility target in all future design years analyzed. The southbound ramp intersection would meet the OHP mobility target in 2022 and 2030, but would fail to meet the OHP mobility target in 2042. The Ehlen Road/Bents Road/Bents Court intersection would perform acceptably and meet mobility targets in all design years. Figure 5-7 shows 2022 and 2030 v/c ratios and vehicle queuing lengths.

Table 5-2. Phase 1 Performance

Mobility Target Phase 1 2022 Phase 1 2030 Phase 1 2042 Location v/c, LOS v/c, LOS v/c, LOS v/c, LOS NB Ramp/Ehlen Rd 0.85, N/A 0.98, N/A 1.15, N/A 1.43, N/A SB Ramp/Ehlen Rd 0.85, N/A 0.66, N/A 0.83, N/A 0.97, N/A Ehlen Rd/Bents Rd/Bents Ct 0.85, LOS D 0.64, LOS C 0.78, LOS D 0.85, LOS D

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Figure 5-7. Phase 1 Alternative – Expected intersection v/c and vehicle queue lengths for 2022 (opening day) and 203014 The primary objective of the Phase 1 project is to improve safety and operation by keeping the interchange off-ramp vehicle queues out of the portions of the ramps needed for safe deceleration from I-5 mainline speeds or onto the I-5 mainline itself. The extended lengths of the off-ramps and capacity improvements at the ramp intersections allow vehicle queues to be safely stored on the off-ramps. Even though the ramp intersections would not have sufficient capacity to meet adopted mobility targets, the underlying safety objective of those targets would be met by the Phase 1 project. It is not known when in the future the remaining improvements to complete the Preferred Alternative (Phase 2) would be funded and constructed and ramp intersections’ mobility targets would be met. ODOT intends to establish the following recommended AMTs at the interchange ramp intersections:

14 Note: Queues illustrated on figure are estimated.

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• I-5 southbound ramp intersection at Ehlen Road This intersection shall not operate at a v/c ratio greater than 0.99, and the 95th percentile vehicle queue on the off-ramp shall not back up into the portion of the ramp needed for safe deceleration from mainline speeds or onto the mainline itself. Both conditions are to be evaluated during the 30th highest annual hour of traffic. • I-5 northbound ramp intersection at Ehlen Road This intersection may operate at a v/c ratio greater than 1.0 between 6:00 a.m. and 6:00 p.m. on an average weekday. For all other hours on an average weekday, the intersection v/c ratio shall not exceed 0.95. In addition, the 95th percentile vehicle queue on the off-ramp during the 30th highest annual hour of traffic shall not back up into the portion of the ramp needed for safe deceleration from mainline speeds or onto the mainline itself. The first step for implementation of the Phase 1 AMTs is to request an amendment to the Marion County Rural TSP through County adoption of the IAMP. Following adoption of the IAMP into the County TSP, ODOT would request that the OTC adopt the IAMP and recommended AMTs and amend the OHP. The AMTs for these intersections would change as noted above after funding and construction of Phase 2. See Appendix M for additional information on the AMT analysis.

5.4.2.2 Phase 2 The second construction phase (Phase 2) includes the remaining interchange improvements of the Preferred Alternative: • Construction of the DDI with new signalized crossover intersections located at the northbound and southbound ramp terminals on Ehlen Road. • Widening Ehlen Road under I-5 to include two travel lanes in each direction with bike and pedestrian facilities. • Lengthening and widening improvements to the southbound on-ramp. • Lengthening and widening improvements to the northbound on-ramp. • Widening improvement to the southbound off-ramp. • Widening improvement to the northbound off-ramp. • Realignment of Ehlen Road, west of I-5, to the north and construction of a new Ehlen Road/Bents Road signalized intersection. • Widening Ehlen Road, east of I-5, to two travel lanes in each direction. • Realignment of Dolores Way to create a new intersection farther east with Ehlen Road. • Changes in circulation and property access to exiting Ehlen Road, west of I-5. Figure 5-8 shows Phase 1 and Phase 2 interchange improvements for the Preferred Alternative. The Phase 2 estimated cost is $29 million. The Phase 2 cost estimate is included in Appendix Q.

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Figure 5-8. Preferred Alternative – Phase 1 and Phase 2 Improvements

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5.5 Access Management This section describes the process and development of an access management plan for the Preferred Alternative and for Phase 1. ODOT’s access management rule15 defines the State’s role in managing access to state highways is to maintain functional use and safety and to preserve the public’s investment. The rule directs ODOT to address access management during the development of an IAMP by developing key access management principles and a methodology that will be used to evaluate how properties abutting the highway may retain or obtain access. ODOT also must include opportunities for affected property owners that abut the highway to review the key access management principles. Ehlen Road is owned by Marion County. The project team determined that the best way to maintain the functional use and safety of the interchange and to preserve the public’s investment was to apply ODOT’s access management rule requirements along relocated Ehlen Road between the relocated intersections of Bents Road and Dolores Way. This area along Ehlen Road between the relocated Bents Road and Dolores Way intersections is defined as the operational area of the interchange. See Figure 5-9.

Figure 5-9. Preferred Alternative Access Management Plan

15 Oregon Administrative Rule 734-051

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5.5.1 Preferred Alternative To develop an access management plan for the Preferred Alternative, the project team engaged in the process described in the rule to address access management during the project planning and preliminary engineering process. The process involved the following activities: • Define access management key principles. • Vet the key principles with affected landowners abutting Ehlen Road. • Develop a methodology for assessing retention of access or creating new accesses along Ehlen Road. • Develop an access management plan for the Preferred Alternative and Phase 1.

5.5.1.1 Key Principles The project team developed key principles that would be used to evaluate how properties abutting Ehlen Road may retain or obtain access during and after IAMP implementation. Based on the project’s goals and objectives, the project team developed the following key principles: 1. Protect the public investment and long-term safety/operations of the interchange and Ehlen Road by reducing or eliminating turn conflicts within the operational area of the interchange. 2. Follow guidance in the Marion County Rural TSP Sub-Area Plan.16 3. Plan for future management of the interchange and adjacent existing and planned land uses. 4. Assist phased construction of interchange improvements with minimal reconstruction. 5. Move toward meeting the ODOT access spacing standards.17 6. Ensure that the location and design of approaches are safe, they reflect the unique needs of each property, and they will serve current and anticipated future traffic. These key principles were sent to all potentially affected landowners within the vicinity of the interchange along Ehlen Road in October 2019. Landowners had an opportunity to review the key principles, ask questions or get clarification from ODOT staff, and provide comments to ODOT. The access management key principles were presented at the stakeholder engagement meeting and project open house on November 13, 2019, and staff were available for questions, clarifications, or comments. No comments were received and no revisions were made to the key principles. Appendix M contains the access management key principles memorandum and stakeholder notification documentation.

5.5.1.2 Methodology ODOT’s access management rule requires development and application of a methodology for determining access to properties abutting the highway and interchange that is consistent with the key principles. ODOT’s access spacing standard for public roads is a minimum of 1,320 feet from the

16 https://www.co.marion.or.us/PW/Engineering/rtsp/Documents/chapter12sub_areaplans.pdf

17 https://www.oregon.gov/ODOT/Engineering/Doc_TechnicalGuidance/AM13-02b.pdf

5-16 October 2020 │ 274-3012-031 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 interchange ramps. The project team started with Key Principle #5: “Move toward meeting the ODOT interchange access spacing standards.” This key principle is consistent with OAR 734-051-1070 that defines implementation of access management strategies as those actions that help in “moving in the direction of the objective [spacing] standards…” This key principle is considered a pass/fail criterion for existing and future accesses; if existing or future access points do not move in the direction of meeting standards, the access should not be permitted. Appendix M includes the Access Management Methodology.

5.5.1.3 Application The existing location of the Bents Road intersection on Ehlen Road is about 100 feet west of the southbound off-ramp intersection and the existing location of the Dolores Way intersection on Ehlen Road is about 250 feet east of the northbound off-ramp. The Preferred Alternative would relocate Ehlen Road west of I-5 through the new Bents Road intersection and along existing Ehlen Road east of I-5 relocated the Dolores Way intersection. Both the relocated Bents Road and relocated Dolores Way intersections would be less than 1,320 feet from the future interchange ramps, but would improve intersection spacing over existing conditions. The ODOT project team evaluated the impact of relocating both county roads to meet the 1,320-foot spacing standard from the interchange ramps. Based on existing land uses, county zoning, and the construction costs and impacts of relocating the county road system, the project team determined that relocating the Bents Road and Dolores Way intersections approximately 800 feet from the interchange ramp intersections moved toward meeting the access management spacing standard, improving current conditions, and complying with ODOT’s access management rule. Furthermore, as part of IAMP implementation, ODOT intends to purchase access rights along relocated and existing Ehlen Road between relocated Bents Road and relocated Dolores Way, effectively ensuring that no new accesses would be allowed to this segment of Ehlen Road. The project team therefore did not further develop the methodology for applying other key principles, as new accesses on Ehlen Road in the interchange operational area would be precluded by ODOT’s purchase of access rights. Access to properties abutting Ehlen Road would be from the county road system, Old Ehlen Road, relocated or old Bents Road, and relocated Dolores Way.

5.5.2 Phase 1 The project team developed an access management plan for Phase 1 that focused on protecting the interchange operational area west of the interchange along existing Ehlen Road. The team determined that ODOT should purchase access control along Ehlen Road between the southbound ramps and the improved Ehlen Road/Bents Road/Bents Court intersection which would include purchasing access rights along the Flying J Truck Stop frontage on the south side of Ehlen Road. Phase 1 would allow the Flying J Truck Stop egress from the truck fueling station to stay open because it improves the transportation performance of the new Ehlen Road/Bents Road/Bents Court intersection. However, the project team was concerned that the Flying J Truck Stop driveway egress may cause safety and operational problems in the future if the remaining improvements to complete the Preferred Alternative (Phase 2) are not funded within a reasonable timeframe. The team wanted to ensure that ODOT had the means to close this access point to improve safety and operation of the interchange in the future. On the east side of the interchange, along Ehlen Road, there is limited road construction and widening in Phase 1. The team determined that access management improvements on the east side should be delayed until Phase 2 when Dolores Way is relocated and Ehlen Road is widened. In the interim between

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Phase 1 construction and Phase 2 funding and implementation, ODOT would rely on the Marion County access management spacing standards to protect operation and safety of the Phase 1 interchange improvements. See Figure 5-10 for the Phase 1 Access Management Plan.

Figure 5-10. Phase 1 Access Management Plan 5.6 Land Use and IAMP Implementation This section describes the land use permitting requirements, IAMP alternate mobility targets, and IAMP implementation steps for the DDI Revised VE Alternative and for Phase 1. This section documents specific land use considerations for the interchange improvements that have been jointly coordinated and agreed upon by Marion County and ODOT. It also outlines local and state IAMP implementation steps.

5.6.1 Local Policy and Permitting The Preferred Alternative modifications to the Aurora Donald Interchange and local roadway system are located within Marion County on land zoned either ID or EFU. The County Rural TSP identifies the need to improve the Aurora Donald Interchange and relocate intersections at Bents Road and Dolores Way on Ehlen Road to improve safety and traffic operations. Local adoption of the IAMP would refine local

5-18 October 2020 │ 274-3012-031 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 policy by providing the location and design of needed improvements within the interchange area. Land use requirements for the Preferred Alternative on state and county roads have been discussed and confirmed with Marion County and are summarized by facility below (see Appendix M for detailed land use analysis). I-5 and Interchange Ramps Preferred Alternative (Phase 1 and Phase 2) improvements to I-5 and interchange ramps within ID and EFU zones are allowed uses; no additional land use permitting is required. Bents Road Relocation Preferred Alternative (Phase 1 and Phase 2) improvements to relocate Bents Road within the ID Zone is an allowed use; no additional land use permitting is required. Ehlen Road West of the Interchange Preferred Alternative (Phase 1 and Phase 2) improvements to widen, signalize, or relocate Ehlen Road within ID and EFU zones west of the interchange are allowed uses; no additional land use permitting is required. Ehlen Road East of the Interchange Phase 1 improvements to widen Ehlen Road within ID and EFU zones east of the interchange is an allowed use; no additional land use permitting is required. Phase 2 improvements to widen Ehlen Road to add travel lanes within the EFU zone would require a conditional use permit. Dolores Way Phase 2 improvement to relocate Dolores Way Road within the EFU zone is an allowed use; no additional land use permitting is required. All Phase 1 improvements are consistent with the County’s currently adopted and acknowledged comprehensive plan and implementing regulations. Specifically, the Rural TSP Aurora/Donald (Fargo) Interchange Area Sub-Area Plan documents the intersection spacing issues related to Bents Road and Ehlen Road and supports the Bents Road realignment to the west. Neither the county roadway realignment nor the proposed improvements to the I-5 mainline would require local land use permits. Phase 2 improvements are anticipated by the Rural TSP and the Interchange Area Sub-Area Plan, but the plans do not include mapped alignments in the locations identified in the IAMP. Local adoption of the IAMP would demonstrate the County’s support of Preferred Alternative implementation, including the specific alignment of Ehlen Road, west of the interchange, and Dolores Way in the east. In addition, prior to construction, widening of Ehlen Road east of the interchange would require County conditional use approval.

5.6.2 Alternative Mobility Targets Phase 1 is funded and anticipated to start construction in 2022. Phase 2 is currently unfunded. The OHP mobility target for the I-5 interchange ramp intersections is 0.85 v/c. Phase 1 interchange improvements would result in v/c ratios at both the northbound and southbound ramp intersections that exceed the state’s mobility targets in 2042. The v/c ratio for the northbound ramp intersection is projected to be 0.98 in 2022 after completion of Phase 1, 1.15 in 2030, and 1.43 in 2042. The v/c ratio for the

October 2020 │ 274-3012-031 5-19 I-5: Aurora Donald Interchange (Exit 278) Interchange Area Management Plan ODOT KN19062 Oregon Department of Transportation – Region 2 southbound ramp intersection is projected to be 0.66 in 2022 after completion of Phase 1, 0.83 in 2030, and 0.97 in 2042. Establishing AMTs for these ramp intersections as part of the Preferred Alternative acknowledges that, while operations would improve over current conditions with construction of Phase 1, the post-construction and 20-year operational forecasts still show a condition that would not meet current OHP targets. The AMTs would simply mirror the anticipated post-Phase 1 operational conditions through the planning horizon. ODOT intends to establish the following recommended AMTs at the interchange ramp intersections for Phase 1 (see Appendix M for additional information on the AMT analysis): • I-5 Southbound Ramp Intersection at Ehlen Road This intersection shall not operate at a v/c ratio greater than 0.99, and the 95th percentile vehicle queue on the off-ramp shall not back up into the portion of the ramp needed for safe deceleration from mainline speeds or onto the mainline itself. Both conditions are to be evaluated during the 30th highest annual hour of traffic. • I-5 Northbound Ramp Intersection at Ehlen Road This intersection may operate at a v/c ratio greater than 1.0 between 6:00 a.m. and 6:00 p.m. on an average weekday. For all other hours on an average weekday, the intersection v/c ratio shall not exceed 0.95. In addition, the 95th percentile vehicle queue on the off-ramp during the 30th highest annual hour of traffic shall not back up into the portion of the ramp needed for safe deceleration from mainline speeds or onto the mainline itself. The Phase 1 AMTs will be reset when Phase 2 of the Preferred Alternative is funded and completed. The transportation analysis shows that full implementation of the Preferred Alternative (Phase 1 and 2) results in v/c ratios at both ramp intersections well below the required 0.85 v/c mobility target. ODOT forecasts that the v/c ratio for the northbound and southbound ramp intersections will be less than 0.40 in 2042. Assuming that this condition remains valid when Phase 2 is constructed, ODOT intends to preserve capacity at this interchange by adopting AMTs that are lower than the current OHP mobility targets. In this instance, where a state/ODOT improvement provides more capacity than will be needed to serve the existing adopted land uses in Marion County’s Comprehensive Plan, lowering the v/c-based AMTs will help preserve the additional capacity for the next increment of growth beyond the 20-year planning horizon. Accordingly, in order to preserve the excess interchange capacity created by Phase 2 that is not needed to serve the existing Marion County Comprehensive Plan land uses through the current planning horizon, ODOT will establish an AMT of 0.6 v/c for both ramp intersections. These AMTs will be adopted by the OTC as part of the IAMP and would replace Phase 1 AMTs when the Phase 2 is constructed. Adopting the 0.6 v/c mobility target for Phase 2 as part of the adopted IAMP will eliminate the need to amend the IAMP and Marion County Rural TSP as part of the Phase 2 project. ODOT will re-evaluate the transportation performance (v/c ratio) of the northbound and southbound ramp intersections during the Phase 2 project development process to ensure that the AMTs remain valid and appropriate. At that time, ODOT will re-evaluate the AMTs for these intersections and determine the appropriate action, based on an updated traffic analysis and in coordination with Marion County. Marion County’s concurrence with the AMTs for both Phase 1 and Phase 2 improvements at the I-5 southbound ramp and I-5 northbound ramp intersections on Ehlen Road will occur when the Marion

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County Board of Commissioners adopts the IAMP as an amendment to the Rural TSP. Following the Marion County’s Comprehensive Plan amendment, which will document and ensure that ODOT’s project plans as described in the IAMP are consistent with the County’s Comprehensive Plan, including the AMTs, ODOT will request the OTC adopt the IAMP as an amendment to the OHP.

5.6.3 IAMP Adoption Process This IAMP will be presented to the OTC for adoption as a state facility plan and minor amendment to the OHP. Prior to adoption by the OTC, ODOT and Marion County worked collaboratively to ensure that the local comprehensive plan, TSP, and Marion County Rural Zoning Code support the Preferred Alternative and that the IAMP recommendations are consistent with local plans and codes. While both the state and the local governments take action to adopt the recommendations of an IAMP, the processes are different, as are the roles and responsibilities at the two levels of government.18 This IAMP guides improvements and funding at the interchange, a state facility, as well as serving as a refinement plan to the Rural TSP for improvements to the local roadway system in the immediate vicinity of the interchange. Marion County and ODOT have determined that the best way for the County to acknowledge the decisions of the IAMP is to: 1. Prepare a local compatibility determination letter that recognizes that Phase 1 is consistent and compatible with the existing adopted comprehensive plan and that no additional local legal actions are necessary to implement the Phase 1 project. The County has determined that Phase 1 transportation solutions in the vicinity of the interchange are consistent with adopted transportation policy, and that the local street system improvements are consistent with the Rural TSP. See Appendix M for the Marion County Phase 1 Land Use Compatibility Statement. 2. Amend the Rural TSP by adopting the IAMP as a refinement plan to ensure consistency between state and local plans. This required a legislative amendment and hearing before the Marion County Board of Commissioners.19 The legislative amendment was considered by the Board at a public hearing on September 30, 2020, and the final ordinance was adopted on October 14, 2020. The adopted Marion County ordinance and findings are included in Appendix R. Specifically, the County action: a. Adopted the IAMP goal statement, acknowledging the need for safe, efficient movement of passenger and freight traffic through the interchange. b. Modified the Aurora/Donald (Fargo) Interchange Area Sub-Area Plan, Rural TSP Chapter 12: i. Adopted the roadway configurations and improvements on Ehlen Road, Bents Road, and Dolores Way shown in Figure 5-3.

18 IAMP adoption process steps detailed in the Guidelines for Interchange Area Management Plans, https://www.oregon.gov/ODOT/Planning/Documents/IAMP_Guidelines.pdf.

19 Legislative amendments are noticed pursuant to the County’s adopted procedures, as well as noticed to the Department of Land Conservation and Development 35 days in advance of the first evidentiary hearing, in accordance with state post-acknowledgement plan amendment procedures.

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ii. Adopted the access management spacing standards for Ehlen Road, documented in Section 5.5, Access Management. c. Agreed to the AMTs for the interchange ramp intersections, documented in Section 5.6.2 and to be adopted by the OTC as part of the OHP. The OTC adoption will entail amending the OHP to include the Aurora Donald IAMP and the associated AMTs as a state facility plan. Upon adoption, the IAMP will become the planning document that governs future improvements in the defined interchange area. Changes to the current land use plan and zoning would need to be found consistent with the adopted AMTs and the IAMP.

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6. PUBLIC INVOLVEMENT This chapter describes the stakeholder and public involvement process for the Aurora Donald Interchange and IAMP. The public involvement effort started with documenting the decision-making process and approach to building awareness about the need for the project, presenting project information and gathering public feedback at key milestones, selecting a preferred interchange alternative, defining a first near-term construction phase (Phase 1), and supporting development of the IAMP. The following public involvement goals were developed: • Communicate complete, accurate, understandable, and timely information to the public throughout the project. • Help the public understand the IAMP and its role in the interchange improvement project. • Actively engage all affected and interested stakeholders about the current challenges of the interchange and gather input on design alternatives for improving it. • Prepare the public for the impact of construction and work toward mitigation of construction impacts. The following sections summarize stakeholder identification, engagement activities, and stakeholder feedback. Appendix S includes a detailed description of stakeholder and public process and events. 6.1 Stakeholders Public outreach efforts were focused on keeping local jurisdictions and their elected officials – Marion County Board of Commissioners, City of Donald, and City of Aurora – updated on the review of interchange concepts and alternatives, ODOT selection of a preferred alternative, design refinements of the full interchange, and definition of Phase 1. The ODOT Mobility Advisory Committee was briefed periodically to ensure the broader freight community was informed and could share concerns. A stakeholder group of interchange area businesses and property owners was convened periodically during 2019 to share project progress and direction, review ODOT work, and to understand comments, questions, and concerns about proposed improvements to the interchange and the county roads. The meetings were open to everyone, but the direct invitation list was built from businesses and property owners in the area. Two public open houses were held to share project direction and to hear comments and concerns from the public about proposed improvements to the interchange and the county roads. 6.2 Outreach Summary The following sections summarize the rounds of outreach that occurred at key project milestones. The briefings and meetings helped ODOT inform area stakeholders and collect comments and questions leading to the selection of the Preferred Alternative and Phase 1. The key milestones were: • Project Introduction • Alternative Development

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• Preferred Alternative Selection • Preferred Alternative Refinement After IAMP adoption, outreach will continue related to final design of the Preferred Alternative and construction to prepare the community for implementation and temporary disruptions resulting from construction.

6.2.1 Project Introduction Public information materials were developed to introduce the project and field work to the public. • Website – a map and background information were included on the project website (www.auroradonaldinterchange.org) • A project information paper was mailed to just over 100 addresses near the interchange, as well as a list of other regional interested parties. The mailer introduced the project purpose and timeline and shared the project website as an ongoing reference for updates or a means to contact the project manager. (January 2019) • Phone calls and emails were made to the City of Donald and City of Aurora administrators, the contact for Friends of French Prairie, the three travel/fuel stations around the interchange, and a few other businesses to gather correct contacts and ask about concerns. Businesses were specifically concerned about access and circulation. Some were interested in future planning for their properties. A contact list was created that would be used to invite area businesses or stakeholders to later meetings. (January through April 2019) • Letters to the property owners where rights of entry were sought for field work or survey were distributed and included the project information. The letters were mailed on various dates beginning in February 2019 and throughout this effort; the March 2019 letters included invitations to the stakeholder engagement meeting held in April 2019. • Staff from the Cities of Donald and Aurora shared information via their respective media and newsletters, as timing allowed, throughout the year.

6.2.2 Alternatives Development After development of interchange concepts and narrowing to two alternative interchange designs, the following stakeholder and public involvement activities were conducted in early 2019: • Briefings to elected bodies and other stakeholders – The project team introduced the project and schedule to the Marion County Board of Commissioners, Mid-Willamette Valley Area Commission on Transportation (MWACT), Donald and Aurora City Councils, and the ODOT Mobility Advisory Committee. At all meetings, there was broad agreement that safety and operations at the interchange needed to be addressed. • Stakeholder Engagement Meeting #1 – The project team invited area stakeholders – property owners, residents, agency representatives, and business owners/managers – through a mailing, emails, and phone calls to an initial stakeholder engagement meeting, to introduce the project and highlight funding limitations, gather feedback on the two interchange concepts that would be further developed and examined, and discuss the purpose of the IAMP. Twenty-one

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stakeholders attended. Generally, there was broad support for the improvements, but there were concerns about potential access changes due to road realignments. Specific concerns were expressed about maintaining the shortest access to trucking-related commercial businesses. Property owners in the southeast quadrant of the interchange were also concerned about how changes in access would affect future development potential. The group discussed the Phase 1 elements that might be built. • Announcement at Marion County Board of Commissioners Town Hall – At a May 2019 town hall meeting, the focus was transportation safety in north Marion County. The ODOT project manager invited attendees to learn more about the interchange project at an upcoming June open house. Locally, residents and businesses were interested in safety, current traffic volumes, and projected traffic volumes at the interchange and on adjacent or nearby county roads.

6.2.3 Preferred Alternative Selection The following stakeholder and public involvement activities were conducted during the process of selecting the Preferred Alternative in spring and summer 2019: • Public Information – The website was updated with maps and meeting dates for the stakeholder engagement meeting and open house. Emails were sent to area stakeholders participating in the stakeholder engagement meetings. Postcards were sent to property owners in the project area announcing the open house. • Outreach to the residential community adjacent to I-5 – An RV resort business/residential community is located adjacent to the northbound off-ramp. There are approximately 130 RV spaces, many with residents/families that have lived there for several years. Project staff delivered meeting invitations to the on-site manager to distribute to residents. • Briefings to elected bodies and other stakeholders – After some early design work and comparison of the two alternatives, the project team updated the MWACT, Marion County Board of Commissioners, the City Councils of Donald and Aurora, and the Mobility Advisory Committee. • Stakeholder Engagement Meeting #2 – A second stakeholder engagement meeting (20 people attended) and open house (15 people attended) were held on June 12, 2019, to gather feedback before ODOT selected a preferred alternative. The project team presented information about the preferred next steps, which included advancing design of the DDI. Access from properties near road realignments continued to be of concern to attendees; this would continue to be explored by the design team. There were also concerns about safety on area county roads. • Open House #1 – A broader drop-in open house was held on June 12, 2019, to present project information to the community and answer questions or document comments. Residents and businesses were interested in safety, current traffic volumes, and future projected traffic volumes at the interchange and adjacent or nearby county roads. Businesses in the area were specifically interested in access. • City of Donald Mayor’s Business Leaders Meeting – The ODOT project manager presented the project and described the two alternatives to area business owners.

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6.2.4 Preferred Alternative Refinement and Phase 1 The project team presented the refined Preferred Alternative to the public after VE study recommendations were incorporated. The following stakeholder and public involvement activities were conducted fall and winter 2019: • Public Information – The website was updated with maps and meeting dates for the stakeholder engagement meeting and open house. Emails were sent to area stakeholders participating in the stakeholder engagement meetings. Postcards were sent to property owners in the project area announcing the open house. GovDelivery emails were sent to the interested parties list. Project information was shared via local agency social media. A newspaper article shared project information and maps in the Statesman Journal. The North Marion School District posted meeting information on the school reader board. • Outreach to the residential community adjacent to I-5 – Project staff contacted the residence manager again to personally invite her to the open house. During the phone call, staff noted her concerns about construction impacts and nighttime noise for residents. Tenants were also mailed invitations to the open house. • Briefings to elected bodies – The project team updated MWACT, the City Councils of Donald and Aurora and the Marion County Board of Commissioners with the design refinements of the DDI and the approach for developing Phase 1. • Stakeholder Engagement Meeting #3 and Open House #2 – A third stakeholder engagement meeting (16 people attended) and open house (24 people attended) were held in November 2019. Safety on area county roads was still a top concern expressed by many local stakeholders. There was some concern about the improved interchange attracting more traffic onto local county roads. Representatives of properties in the southeast quadrant had questions about access and placement of the realigned Dolores Way as it affects potential redevelopment. Stakeholders were assured that farm equipment would have similar access in the future. Generally, the design for the full interchange including refinements since summer 2019 and the approach for developing Phase 1 improvements were supported by area stakeholders that attended. ODOT stated it would continue to work on individual access and ROW acquisition during design.

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7. REFERENCES

Ma, L., I. Madin, K. Olson, R. Watzig, R. Wells, and A. Niem, et al. 2009. Oregon Geologic Data Compilation - Release 5, (statewide). Oregon Department of Geology and Mineral Industries.

Marion County. 2005. Marion County Rural Transportation System Plan 2005 Update. https://www.co.marion.or.us/PW/Engineering/rtsp. Accessed January 7, 2019.

MTI (Mineta Transportation Institute). 2012. Low-Stress Bicycling and Network Connectivity, Report 11-19. Mineta Transportation Institute, San Jose University, San Jose, CA. https://transweb.sjsu.edu/sites/default/files/1005-low-stress-bicycling-network-connectivity.pdf.

ODOT (Oregon Department of Transportation). 2013. Interchange Area Management Plan Guidelines. https://www.oregon.gov/ODOT/Planning/Documents/IAMP_Guidelines.pdf

ODOT. 2013. Interchange Area Management Plan Guidelines. https://www.oregon.gov/ODOT/Planning/Documents/IAMP_Guidelines.pdf. Accessed February 3, 2020.

ODOT. 2015. 1999 Oregon Highway Plan, Including amendments November 1999 through May 2015. Appendix C Table 17: Minimum Spacing Standards Applicable To Freeway Interchanges with Two- Lane Crossroads, p. 213. https://www.oregon.gov/odot/planning/pages/plans.aspx. Accessed February 3, 2020.

ODOT. 2019. Analysis Procedures Manual, Version 2. Oregon Department of Transportation, Salem, OR. https://www.oregon.gov/ODOT/Planning/Documents/APMv2.pdf

OSU (Oregon State University). n.d. Oregon Biodiversity Information Center. https://inr.oregonstate.edu/orbic. Accessed February 3, 2020.

StreamNet. n.d. Fish Data for the Northwest Interactive Mapper, https://www.streamnet.org/. Accessed February 3, 2020.

TRB (Transportation Research Board). 2016. Highway Capacity Manual, Sixth Edition: A Guide for Multimodal Mobility Analysis, Transportation Research Board, Washington, D.C.

USFWS (U.S. Fish and Wildlife Service). n.d. Information Planning and Conservation (IPaC) database, Trust Resources Report. https://ecos.fws.gov/ipac/. Accessed February 3, 2020.

USFWS. n.d. Environmental Conservation Online System (ECOS) Critical Habitat for Threatened and Endangered Species. https://ecos.fws.gov/ecp/report/table/critical-habitat.html. Accessed February 3, 2020. n.d. = not dated

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