Costco Wholesale Specific Plan TRAFFIC IMPACT ANALYSIS

Costco Wholesale Specific Plan

TRAFFIC IMPACT ANALYSIS REPORT

Prepared for

City of San Marcos

1 Civic Center Drive, San Marcos, CA 92069

Prepared by

5050 Avenida Encinas, Suite 260, Carlsbad, CA 92008 CONTACT: BOB DAVIS 760.476.9193 [email protected]; or DAVID MIZELL 760.476.9193 [email protected].

Final Draft: September 30, 2009

JN 55-100633.001

TABLE OF CONTENTS

Introduction ...... 1

Analysis Methodology ...... 4

Existing Conditions ...... 7

Proposed Project ...... 11

Existing Plus Project Conditions...... 14

Existing Plus Cumulative Conditions – Without and With Project ...... 18

Significant Impacts and Mitigation...... 28

Caltrans ILV Analysis...... 29

Construction Traffic Analysis...... 31

Summary and Conclusions ...... 33

APPENDICES

Appendix A: SANTEC/ITE Guidelines Roadway Segment Capacity and LOS Criteria Appendix B: Traffic Count Data Appendix C: Existing Conditions HCM Worksheets Appendix D: SANDAG Trip Generation Rates Appendix E: Existing Plus Project Conditions HCM Worksheets Appendix F: Existing Plus Cumulative Without Project Conditions HCM Worksheets – Without SR-78 / Nordahl Road Interchange Improvements Appendix G: Existing Plus Cumulative With Project Conditions HCM Worksheets – Without SR-78 / Nordahl Road Interchange Improvements Appendix H: Existing Plus Cumulative Without Project Conditions HCM Worksheets – With SR-78 / Nordahl Road Interchange Improvements Appendix I: Existing Plus Cumulative With Project Conditions HCM Worksheets – With SR-78 / Nordahl Road Interchange Improvements Appendix J: Caltrans ILV Analysis Calculation Worksheets

LIST OF EXHIBITS

Exhibit 1: Regional Project Vicinity...... 2 Exhibit 2: Project Site Plan...... 3 Exhibit 3: Project Study Area...... 5 Exhibit 4: Existing Intersection Lane Geometries ...... 8 Exhibit 5: Existing Conditions Traffic Volumes...... 10 Exhibit 6: Project Trip Distribution ...... 15 Exhibit 7: Project Trip Assignment...... 16 Exhibit 8: Existing Plus Project Conditions Traffic Volumes...... 17 Exhibit 9: Cumulative Project Locations ...... 20 Exhibit 10: Cumulative Project Trips...... 21 Exhibit 11: Existing Plus Cumulative Without Project Conditions Traffic Volumes ...... 23 Exhibit 12: Existing Plus Cumulative With Project Conditions Traffic Volumes ...... 24 Exhibit 13: Future Intersection Lane Geometries With Planned SR-78 / Nordahl Road Interchange Improvements...... 27

LIST OF TABLES

Table 1: Level of Service & Delay Ranges ...... 6 Table 2: Daily Level of Service Thresholds for Roadway Segments ...... 6 Table 3: Existing Peak Hour Intersection Conditions...... 9 Table 4: Existing Daily Roadway Segment Conditions ...... 9 Table 5: Proposed Project Trip Generation – Ground-to-Plan Method ...... 12 Table 6: Proposed Project Trip Generation – Current Plan-to-Proposed Plan Method ...... 13 Table 7: Existing Plus Project Peak Hour Intersection Conditions ...... 14 Table 8: Existing Plus Project Daily Roadway Segment Conditions ...... 18 Table 9: Cumulative Projects Trip Generation...... 19 Table 10: Existing Plus Cumulative Peak Hour Intersection Conditions – Without SR-78 / Nordahl Road Interchange Improvements ...... 22 Table 11: Existing Plus Cumulative Daily Roadway Segment Conditions – Without SR-78 / Nordahl Road Interchange Improvements ...... 25 Table 12: Existing Plus Cumulative Peak Hour Intersection Conditions – With SR-78 / Nordahl Road Interchange Improvements ...... 26 Table 13: Existing Plus Cumulative Daily Roadway Segment Conditions – With SR-78 / Nordahl Road Interchange Improvements ...... 28 Table 14: ILV Methodology Performance Criteria...... 29 Table 15: Caltrans ILV Analysis Summary ...... 30 Table 16: Summary of Construction Truck Hauling Activity ...... 31 INTRODUCTION

As required by the City of San Marcos, this traffic impact study has been prepared in accordance with the City’s General Plan Circulation Element and SANTEC/ITE traffic study guidelines.

This traffic impact analysis includes the following study scenarios:

• Existing Conditions • Existing Plus Project Conditions • Existing Plus Cumulative Conditions Without Project • Existing Plus Cumulative Conditions With Project

Project Description

The proposed project consists of replacing the existing 134,818 square-foot Costco warehouse building and 49,069 square-foot Harley Davidson building with a new 148,233 Costco warehouse building, a satellite fuel station with 16 pumps and a satellite car wash. The project will take access from four driveways located on Center Drive. Exhibit 2 shows the project site plan.

Study Area

According to SANTEC/ITE traffic study guidelines, intersections and roadway segments where 50 or more peak hour trips are forecast to be added shall be selected for inclusion in this analysis. A total of five intersections and three roadway segments were identified for inclusion in this traffic study. Based on the requirements of the SANTEC/ITE traffic study guidelines and the concurrence of City of San Marcos staff, the study area consists of the following five intersections and three roadway segments:

Intersections 1) Center Drive / Avenida Ricardo 2) Nordahl Road / Center Drive 3) Nordahl Road / Montiel Road 4) Nordahl Road / SR-78 Westbound Ramps 5) Nordahl Road / SR-78 Eastbound Ramps

Roadway Segments 1) Center Drive, West of Nordahl Road 2) Nordahl Road, Center Drive to Montiel Road 3) Nordahl Road, Montiel Road to SR-78

The proposed project study area intersections are shown graphically in Exhibit 3.

ANALYSIS METHODOLOGY

In accordance with SANTEC/ITE traffic study guidelines and City of San Marcos requirements, this study analyzes the followings study scenarios:

• Existing Conditions – Analysis of existing traffic count volumes, intersection geometry and existing roadway network.

• Existing Plus Project – Analysis of existing traffic volumes overlaid with traffic generated by the proposed project.

• Existing Plus Cumulative Conditions Without Project – Analysis of existing traffic volumes overlaid with traffic associated with approved or pending projects anticipated to be constructed within the next several years (by 2015). Analysis of existing plus cumulative conditions is evaluated both without and with the planned Nordahl Road / SR-78 interchange improvements.

• Existing Plus Cumulative Conditions With Project – Analysis of existing traffic volumes overlaid with cumulative project traffic and traffic generated by the proposed project. Analysis of existing plus cumulative conditions is evaluated both without and with the planned Nordahl Road / SR-78 interchange improvements.

Analysis of all intersections and roadway segments in the project study area is based on the SANTEC/ITE traffic study guidelines, and is consistent with the City of San Marcos General Plan Circulation Element. As required, the 2000 Highway Capacity Manual (HCM) operation methodology for Signalized and Unsignalized Intersections was used to determine the operating Levels of Service (LOS) of the study intersections. The SYNCHRO software package was used to evaluate the study intersections using the HCM methodology. The HCM methodology describes the operation of an intersection using a range of levels of service (LOS) from LOS A (free-flow conditions) to LOS F (severely congested conditions), based on corresponding delay per vehicle thresholds for signalized and unsignalized intersections shown in Table 1. The City of San Marcos considers LOS D or better to be acceptable intersection operating conditions during peak traffic periods.

Table 1 Level of Service & Delay Ranges

Delay (seconds/vehicle) LOS Signalized Intersections Unsignalized Intersections A < 10.0 < 10.0

B > 10.0 to < 20.0 > 10.0 to < 15.0

C > 20.0 to < 35.0 > 15.0 to < 25.0

D > 35.0 to < 55.0 > 25.0 to < 35.0

E > 55.0 to < 80.0 > 35.0 to < 50.0

F > 80.0 > 50.0 Source: 2000 Highway Capacity Manual.

A daily roadway segment analysis was conducted for all study area roadways, in accordance with the City of San Marcos General Plan Circulation Element and SANTEC/ITE guidelines. The roadway segment level of service criteria is included in Table 2. Excerpts from the SANTEC/ITE traffic impact study guidelines that summarize the capacity thresholds by roadway segment and level of service criteria are provided in Appendix A.

Table 2 Daily Level of Service Thresholds for Roadway Segments

Level of Service Classification / Lanes A B C D E

Prime Arterial / 6 25,000 35,000 50,000 55,000 60,000

Major Arterial / 4 15,000 21,000 30,000 35,000 40,000

Secondary Arterial / 5 12,500 17,500 25,000 31,300 37,500

Secondary Arterial / 4 10,000 14,000 20,000 25,000 30,000

Collector / 2 + TWLTL (1) 5,000 7,000 10,000 13,000 15,000

Collector / 2 (2) 2,500 3,500 5,000 6,500 8,000 Source: SANTEC/ITE Guidelines for Traffic Impact Studies in the San Diego Region, 2000. (1) TWLTL = Two-Way Left-Turn Lane (center lane) (2) With fronting commercial or residential property.

According to the City of San Marcos General Plan Circulation Element, the City’s goal for acceptable service standards during daily periods is LOS D for all roadway segments.

6 EXISTING CONDITIONS

Existing Land Use

The project site is currently occupied by the existing Costco Warehouse and Harley Davidson buildings. The project site is currently zoned for Community Commercial use.

Existing Roadway Circulation System

A detailed field review was conducted to determine the existing intersection geometry, traffic control devices, signal phasing and other factors, which may affect intersection or roadway segment capacity. The existing intersection geometry is illustrated in Exhibit 4. The following is a detailed description of roadways in the study area.

State Route 78 (SR-78) provides regional access to San Marcos as a six-lane major freeway facility, generally oriented in an east-west direction. Regional project access is provided at the Nordahl Road / SR-78 interchange.

Nordahl Road is constructed as a two-land to four-lane arterial oriented in a north-south direction, extending south from El Norte Parkway in the City of Escondido through unincorporated areas and through the eastern side of the City of San Marcos to Mission Road in the City of Escondido, where Nordahl Road transitions to Auto Park Way. Nordahl Road is classified in the City of San Marcos General Plan Circulation Element as a Major Arterial from the northern City boundary (near Knob Hill Rod) to Montiel Road, and as a Prime Arterial from Montiel Road to Mission Road.

Center Drive is constructed as a two-lane to four-lane roadway oriented in an east-west direction extending west from Nordahl Road and circumnavigating the Nordahl Marketplace Shopping Center to Montiel Road immediately west of Nordahl Road. Center Drive is not included in the City’s General Plan Circulation Element.

Existing Levels of Service

To determine the existing operation of the study intersections, intersection movement counts were taken on a typical weekday during the a.m. (7:00 to 9:00 a.m.) and p.m. (4:00 to 6:00 p.m.) peak periods. Exhibit 5 shows the existing Average Daily Traffic (ADT) volumes and a.m. and p.m. peak one-hour volumes at each of the study intersections based on the traffic count data collected for this study. Detailed traffic count data is contained in Appendix B.

Table 3 summarizes the existing a.m. and p.m. peak hour intersection LOS of the study intersections based on the existing peak hour intersection volumes and existing intersection geometry. Detailed HCM calculation sheets are contained in Appendix C.

As shown in Table 3, all study intersections are currently operating at an acceptable LOS (LOS D or better) during the a.m. and p.m. peak hours.

Table 3 Existing Peak Hour Intersection Conditions

AM Delay – LOS PM Delay – LOS Study Intersection (sec.) (sec.) Center Drive / Avenida Ricardo 18.9 – B 18.4 – B Nordahl Road / Center Drive 14.5 – B 30.4 – C Nordahl Road / Montiel Road 30.2 – C 31.8 – C Nordahl Road / SR-78 Westbound Ramps 30.4 – C 34.4 – C Nordahl Road / SR-78 Eastbound Ramps 30.6 – C 32.7 – C

It must be noted that although the study intersections are shown to operate at acceptable levels of service based on the HCM methodology, there is currently substantial congestion and queuing on Nordahl Road in the vicinity of the SR-78 interchange, particularly during the p.m. peak hour. This congestion is largely due to the closely spaced intersections and short left-turn bays at the ramp intersections. A result of the queuing problem on Nordahl Road is that it limits the number of vehicles that can travel through the intersections; therefore, demand during the p.m. peak hour may be higher than what the traffic count data shows at these locations.

The planned replacement of the Nordahl Road bridge over SR-78 and associated interchange improvements will alleviate much of the current congestion and queuing problems in the vicinity of Nordahl Road and SR-78. In addition, the City is planning to improve the signal interconnection along Nordahl Road and is considering implementation of adaptive signal control on Nordahl Road in the vicinity of the SR-78 interchange.

Daily roadway segment levels of service were evaluated based on the volume-to-capacity ratio calculations. The capacity of the roadway is an approximation of the daily volumes that can be carried by the roadway according to its functional classification. Table 4 presents the results of the existing conditions daily roadway segment level of service analysis.

As shown in Table 4, all study roadway segments currently operate at acceptable levels of service (LOS D or better).

Table 4 Existing Daily Roadway Segment Conditions

Class Daily Existing Roadway Segment V/C LOS (# Lanes) Capacity ADT Center Drive West of Nordahl Road Secondary (4) 30,000 12,726 0.424 B

Nordahl Center Drive to Montiel Road Major (4) 40,000 15,558 0.389 B Road Montiel Road to SR-78 Major (6) * 50,000 * 35,640 0.713 C * Although this segment currently provides only four through lanes, due to the short length (approximately 300 feet) and multiple turn lanes in both directions of travel, the daily capacity of this segment was increased to reflect the capacity for a six-lane Major Arterial.

PROPOSED PROJECT

The proposed Costco Wholesale Specific Plan project consists of replacing the existing 134,818 square- foot Costco warehouse building and 49,069 square-foot Harley Davidson building with a new 148,233 Costco warehouse building, a satellite fuel station with 16 pumps and a satellite car wash.

Project Trip Generation

To determine the trips forecast to be generated by the proposed project, April 2002 SANDAG Trip Generation rates were utilized in accordance with the City of San Marcos guidelines. The SANDAG (Not So) Brief Guide of Vehicular Traffic Generation Rates for the San Diego Region (April 2002) showing the trip generation rates for the proposed land uses is provided in Appendix D. Table 5 summarizes the project trip generation for the proposed Costco Wholesale Specific Plan project.

The trip generation rate for the proposed Costco expansion with fuel station and car wash was changed from Discount Club to Community Shopping Center since the Discount Club rate does not include ancillary uses such as a fueling station and car wash. The Community Shopping Center rate, which is higher than the Discount Club rate, is applied to the daily and p.m. peak hour trips for the proposed uses.

It has been verified from Costco-specific trip generation research conducted by Kittelson and Associates that the SANDAG Community Shopping Center trip generation rate is very similar to that of a Costco with a fueling station. Since the Costco store is not open for business during the a.m. peak hour, the fueling station and car wash trips were calculated separately using SANDAG trip generation rates and as verified from Costco-specific trip generation research. It should be noted that driveway counts taken over a two-day period provided confirmation that the SANDAG Discount Club trip rate was appropriate for the existing Costco store.

As summarized in Table 5, the proposed project is forecast to generate a net decrease of 82 trips per day as compared to the existing trip generation. The proposed project is forecast to generate a net increase of 135 trips during the a.m. peak hour and a net increase of 112 trips during the p.m. peak hour as compared to the existing trip generation.

It must be noted that the trip generation developed for evaluation of traffic operations with the proposed project is based on a ground-to-proposed plan method, which compares the currently active uses with the proposed uses. The ground-to-proposed plan method used in the traffic analysis is a conservative approach and does not take into account the full trip generation potential of the current Costco Wholesale Specific Plan. The Costco Wholesale Specific Plan site includes a 2.1-acre lot that is currently undeveloped, which will be absorbed into the proposed project. Another method to develop the trip generation is the current plan-to-proposed plan method, which compares the current Costco Wholesale Specific Plan trip generation with the trip generation of the proposed project. This method estimates the full potential trip generation of the existing site, which includes a community commercial use for the existing Harley Davidson building and the currently undeveloped 2.1-acre site adjacent to Costco. The current plan-to-proposed plan trip generation method is shown in Table 6 and is for informational purposes only.

Table 5 Proposed Project Trip Generation Ground-to-Plan Method (used in traffic analysis)

Weekday AM Peak Hour of Weekday PM Peak Hour of SANDAG Land Use Daily Facility Size Adjacent Street Traffic Adjacent Street Traffic (Trips per unit) Trips Total In Out Total In Out EXISTING USES Costco (without Fuel Station) 8,088 81 57 24 728 364 364 Discount Club 134,800 Pass-by Trips (15%) -1,214 - - - -110 -55 -55 (60/1,000 SF) SF Total Trips 6,874 81 57 24 618 309 309 Harley Davidson Auto Sales 49,100 2,456 49 34 15 196 78 118 Total Trips (50/1,000 SF) SF 2,456 49 34 15 196 78 118 Total Primary Trips 9,330 130 91 39 814 387 427 PROPOSED USES Costco (with Fuel Station) 11,856 119 83 36 1,186 593 593 Community Shopping 148,200 Pass-by Trips (22%) Center -2,608 - - - -260 -130 -130 SF (80/1,000 SF) Total Proposed Trips 9,248 119 83 36 926 463 463 Costco Fuel Station Gasoline - 168 84 84 - - - (Older Service Station 16 Pass-by Trips (28%) - -48 -24 -24 Design) Positions Total Proposed Trips (150/fueling space) - 120 60 60 Costco Car Wash - 36 18 18 - - - Car Wash (Automatic) 1 Pass-by Trips (28%) - -10 -5 -5 (900 / Site) Position Total Proposed Trips - 26 13 13 Total Primary Trips 9,248 265 156 109 926 463 463 TRIP DIFFERENCE (PROPOSED - EXISTING) Total Primary Existing Trips 9,330 130 91 39 814 387 427 Total Primary Proposed Trips 9,248 265 156 109 926 463 463 Net New Primary Trips (Proposed - Existing) (1) -82 135 65 70 112 76 36 (1) Net new primary trips are used in the analysis of peak hour intersection and daily roadway segment operations.

Table 6 Proposed Project Trip Generation Current Plan-to-Proposed Plan Method (for informational purposes only)

Weekday AM Peak Hour of Weekday PM Peak Hour of SANDAG Land Use Daily Facility Size Adjacent Street Traffic Adjacent Street Traffic (Trips per unit) Trips Total In Out Total In Out EXISTING USES Costco (without Fuel Station) 8,088 81 57 24 728 364 364 Discount Club 134,800 Pass-by Trips (15%) -1,214 - - - -110 -55 -55 (60/1,000 SF) SF Total Trips 6,874 81 57 24 618 309 309 Harley Davidson Building Community Shopping 3,928 157 94 63 393 196 197 49,100 Pass-by Trips (30%) Center -1,178 -47 -28 -19 -118 -59 -59 SF Total Trips (80/1,000 SF) 2,750 110 66 44 275 137 138 Undeveloped 2.11-Acre Site Community Shopping 1,477 59 35 24 148 74 74 18,463 Pass-by Trips (30%) Center -443 -18 -11 -7 -44 -22 -22 SF Total Trips (80/1,000 SF) 1,034 41 25 17 104 52 52 Total Primary Trips 10,659 232 147 85 998 499 499 PROPOSED USES Costco (with Fuel Station) Community Shopping 11,856 119 83 36 1,186 593 593 148,200 Pass-by Trips (22%) Center -2,608 - - - -260 -130 -130 SF Total Proposed Trips (80/1,000 SF) 9,248 119 83 36 926 463 463 Costco Fuel Station Gasoline - 168 84 84 - - - (Older Service Station 16 Pass-by Trips (28%) - -48 -24 -24 Design) Positions Total Proposed Trips (150/fueling space) - 120 60 60 Costco Car Wash - 36 18 18 - - - Car Wash (Automatic) 1 Pass-by Trips (28%) - -10 -5 -5 (900 / Site) Position Total Proposed Trips - 26 13 13 Total Primary Trips 9,248 265 156 109 926 463 463 TRIP DIFFERENCE (PROPOSED - EXISTING) Total Primary Existing Trips 10,659 232 147 85 998 499 499 Total Primary Proposed Trips 9,248 265 156 109 926 463 463 Net New Primary Trips (Proposed - Existing) (1) -1,411 33 9 24 -72 -36 -36 *This method estimates the full potential trip generation of the existing site, which includes a community commercial use for the existing Harley Davidson building and the currently undeveloped 2.1-acre site adjacent to Costco.

Project Trip Distribution

Project traffic was manually distributed on the roadway network based on understanding of the project study area and existing traffic patterns. Exhibit 6 shows the project trip distribution percentages for the proposed Costco Wholesale Specific Plan project.

Project Trip Assignment

Utilizing the project trip distribution shown in Exhibit 6, the forecast project-generated trips were assigned to the roadway network. Exhibit 7 illustrates the forecast assignment of project-generated peak hour trips and daily trips.

EXISTING PLUS PROJECT CONDITIONS

To determine the existing plus project operating conditions at the study intersections, the project- generated trips were added to the existing condition volumes. Exhibit 8 shows the existing plus project a.m. and p.m. peak hour and ADT volumes.

Table 7 summarizes the existing plus project a.m. and p.m. peak hour intersection LOS. Detailed HCM calculation sheets are contained in Appendix E. As shown in Table 7, the addition of project- generated trips is not forecast to result in a change in LOS from acceptable to deficient at any of the study intersections. Consistent with existing conditions, all intersections would continue to operate at LOS D or better with the addition of traffic generated by the proposed project.

Table 7 Existing Plus Project Peak Hour Intersection Conditions

Change in Existing Conditions Existing Plus Project Delay Study Intersection AM PM AM PM AM PM Delay-LOS Delay-LOS Delay-LOS Delay - LOS Center Drive / Avenida Ricardo 18.9 – B 18.4 – B 20.5 – C 17.9 – B 1.6 -0.5

Nordahl Road / Center Drive 14.5 – B 30.4 – C 21.2 – C 31.2 – C 6.7 0.8

Nordahl Road / Montiel Road 30.2 – C 31.8 – C 29.7 – C 31.6 – C -0.5 -0.2 Nordahl Road / SR-78 Westbound 30.4 – C 34.4 – C 30.4 – C 34.8 – C 0.0 0.4 Ramps Nordahl Road / SR-78 Eastbound 30.6 – C 32.7 – C 31.2 – C 33.5 – C 0.6 0.8 Ramps Note: Deficient intersection operation shown in bold.

As previously noted in the Existing Conditions section, the HCM level of service analysis results do not reflect the current congestion and queuing that occurs on Nordahl Road near the SR-78 interchange during the p.m. peak hour. Although the analysis results under existing plus project conditions show that the study intersections would continue operating at acceptable levels of service, the addition of project-generated traffic to existing volumes would worsen the existing queuing problem somewhat. The planned replacement of the Nordahl Road bridge over SR-78 and associated interchange improvements will alleviate much of the current congestion and queuing problems in the vicinity of Nordahl Road and SR-78.

The results of the existing plus project conditions roadway segment level of service analysis is presented in Table 8. Consistent with existing conditions, all of the roadway segments are forecast to operate at acceptable levels of service (LOS D or better) with the proposed project. Please note that the proposed Costco expansion project would result in a net decrease in daily trips; therefore, daily traffic volumes with the proposed project are projected to be slightly lower than the existing ADT volumes for the study roadway segments.

Table 8 Existing Plus Project Daily Roadway Segment Conditions

Existing Existing Plus Project Roadway Segment Class Capacity (# Lanes) ADT V/C LOS ADT V/C LOS Change in V/C Center West of Nordahl Secondary 30,000 12,726 0.424 B 12,650 0.422 B -0.003 Drive Road (4) Center Drive to Major (4) 40,000 15,558 0.389 B 15,502 0.388 B -0.001 Nordahl Montiel Road Road Montiel Road to Major (6) * 50,000 * 35,640 0.713 C 35,587 0.712 C -0.001 SR-78 * Although this segment currently provides only four through lanes, due to the short length (approximately 300 feet) and multiple turn lanes in both directions of travel, the daily capacity of this segment was increased to reflect the capacity for a six-lane Major Arterial.

EXISTING PLUS CUMULATIVE CONDITIONS – WITHOUT AND WITH PROJECT

To determine the existing plus cumulative conditions in the project study area, forecast project traffic associated with City of San Marcos, City of Escondido and County of San Diego approved or pending projects was added to existing traffic volumes. This formed the base conditions upon which traffic generated by the proposed project was added. The City of San Marcos, the City of Escondido, and the County of San Diego provided information for 15 cumulative projects that would generate traffic in the study area, which are summarized in Table 9. Exhibit 9 shows the locations of the cumulative projects. Exhibit 10 shows the peak hour and daily cumulative project volumes.

As presented in Table 9, the cumulative projects are forecast to generate approximately 83,915 trips per day, which includes approximately 7,280 a.m. peak hour trips and approximately 8,898 p.m. peak hour trips.

Table 9 Cumulative Projects Trip Generation Land Daily AM AM PM PM Project Intensity Unit AM In PM In Use Trips Trips Out Trips Out City of San Marcos Projects University District (1) 1. Mixed Use 16,955 1,013 601 412 1,728 812 915 SP CSUSM Master 2. University 6,026 students 14,462 1,446 1,157 289 1,302 390 911 Plan (2) Nordahl Medical 3. Medical Office 56.2 KSF 2,810 169 135 34 309 93 216 Center Corporate Office Standard Office 4. 25 KSF 500 70 63 7 65 13 52 Building Building Campus Pointe Large Office 5. 112 KSF 1,904 248 223 25 267 53 213 Office Building Building Civic View Standard Office 6. 99.5 KSF 1,990 279 251 28 259 52 207 Corporate Center Building City of Escondido Projects Robertson's Concrete Industrial / 7. 2.02 acres 606 27 12 15 11 8 3 Manufacturing Manufacturing Plant Meyers Industrial Light Industrial 8. 106.384 KSF 395 72 64 8 76 16 60 Development Park Escondido Research & Research & 9. 821.9 KSF 9,863 1,282 1,154 128 1,282 256 1,026 Technology Development Center (ERTC) Hospital 453 beds 9,060 724 507 217 906 362 544 Palomar Medical 10. Medical Office 160 KSF 8,000 480 384 96 880 264 616 Center West Total Project Trips 17,060 1,204 891 313 1,786 626 1,160 Harmony Grove Industrial/ 11. Rd. Business 17.4 acres 3,480 418 334 84 418 84 334 Business Park Park ERTC SP 12. Medical Office Medical Office 44.393 KSF 2,220 133 106 27 244 73 171 Building Harmony Grove Single-Family 13. 22 DU 220 18 5 13 22 15 7 Rd. Residential Detached County of San Diego Projects Single-Family 611 DU 6,110 489 147 342 611 428 183 Detached Estate 99 DU 1,188 95 29 67 119 83 36 Residential Harmony Grove Apartments 32 DU 192 15 3 12 17 12 5 14. Village Office 16.5 KSF 330 46 42 5 43 9 34 Specialty Retail 25 KSF 1,000 30 18 12 90 45 45 Institutional mixed acres 470 55 43 11 35 6 29 Total Project Trips 9,290 730 281 449 915 583 332 Harmony Grove Single-Family 15. 216 DU 2,160 173 52 121 216 151 65 Meadows Detached Total Cumulative Project Trips 83,915 7,280 5,329 1,952 8,898 3,225 5,673 (1) The project is assumed to be approximately 15% built under cumulative conditions; at full build-out, the project would consist of 3,400 DU, 1 million s.f. commercial, 935,000 s.f. office, 450 hotel rooms, 30,000 s.f. community center, and an 850-student elementary school. (2) According to the CSUSM Campus Transportation Plan (Nelson Nygaard & Associates, Dec. 2007), planned student enrollment by 2015 at CSU San Marcos would have increased by approximately 6,026 students from the 2007/2008 academic year.

To determine the future cumulative and project impacts at the SR-78 / Nordahl Road interchange, the existing plus cumulative analysis evaluates future traffic conditions under two network scenarios:

• Without SR-78 / Nordahl Road Interchange Improvements (existing roadway network) • With SR-78 / Nordahl Road Interchange Improvements (ramp intersections only)

Exhibit 11 shows the existing plus cumulative without project daily and a.m. and p.m. peak hour traffic volumes. To determine the existing plus cumulative operating conditions with the proposed project, the forecast project-generated trips were added to the existing plus cumulative traffic volumes. Exhibit 12 shows the existing plus cumulative with project daily and a.m. and p.m. peak hour traffic volumes.

Existing Plus Cumulative Level of Service Analysis – Without SR-78 / Nordahl Road Interchange Improvements

The existing plus cumulative level of service analysis without the planned SR-78 / Nordahl Road interchange improvements assumes no improvements are made to the existing study area roadway network.

Table 10 summarizes the existing plus cumulative peak hour intersection LOS without the SR-78 / Nordahl Road interchange improvements, without and with the proposed project. Detailed HCM calculation sheets are contained in Appendix F and G for the without and with project scenarios, respectively.

Table 10 Existing Plus Cumulative Peak Hour Intersection Conditions Without SR-78 / Nordahl Road Interchange Improvements

Without Project With Project Change in Delay (1) Study Intersection AM Delay PM Delay AM Delay PM Delay AM PM – LOS (1) – LOS (1) – LOS (1) – LOS (1) Center Drive / Avenida Ricardo 19.0 – B 18.4 – B 20.6 – C 17.9 – B 1.6 -0.5 (2)

Nordahl Road / Center Drive 11.4 – B 29.3 – C 17.5 – B 30.6 – C 6.1 1.3

Nordahl Road / Montiel Road 27.4 – C 31.0 – C 27.1 – C 30.9 – C -0.3 (3) -0.1(3)

Nordahl Road / SR-78 Westbound Ramps 37.4 – D 57.0 – E 37.9 – D 58.6 – E 0.5 1.6

Nordahl Road / SR-78 Eastbound Ramps 40.8 – D 58.8 – E 42.3 – D 62.8 – E 1.5 4.0 Note: Deficient intersection operation shown in bold. Change in delay shown in bold indicates a project significant impact. (1) Seconds of delay per vehicle. (2) The addition of project traffic to the east-west through lanes results in an overall lower average delay for the intersection, which implies that project traffic is being added to non-critical movements at the intersection. (3) The addition of project traffic to the north-south through lanes results in an overall lower average delay for the intersection, which implies that project traffic is being added to non-critical movements at the intersection.

As shown in Table 10, the following intersections are forecast to operate at deficient levels of service without the SR-78 / Nordahl Road interchange improvements, under existing plus cumulative conditions both without and with the proposed project:

• Nordahl Road / SR-78 Westbound Ramps • Nordahl Road / SR-78 Eastbound Ramps

The increase in delay at the Nordahl Road / SR-78 Westbound Ramps resulting from the addition of project-generated traffic to existing plus cumulative volumes is less than the 2.0-second significance threshold; therefore, traffic generated by the proposed project does not result in a significant impact at this intersection.

The addition of project-generated traffic to existing plus cumulative volumes increases delay by more than 2.0 seconds during the p.m. peak hour at the deficient intersection of Nordahl Road / SR- 78 Eastbound Ramps; therefore, traffic generated by the proposed project results in a significant impact at this location.

Table 11 presents the results of the existing plus cumulative conditions roadway segment level of service analysis without the SR-78 / Nordahl Road interchange improvements, without and with the proposed project.

Table 11 Existing Plus Cumulative Daily Roadway Segment Conditions Without SR-78 / Nordahl Road Interchange Improvements

Without Project With Project Roadway Segment Class Capacity (# Lanes) ADT V/C LOS ADT V/C LOS Change in V/C Center West of Nordahl Secondary 30,000 12,792 0.426 B 12,716 0.424 B -0.003 Drive Road (4) Center Drive to Major (4) 40,000 19,888 0.497 B 19,832 0.496 B -0.001 Nordahl Montiel Road Road Montiel Road to Major (6) * 50,000 * 40,199 0.804 D 40,146 0.803 D -0.001 SR-78 * Although this segment currently provides only four through lanes, due to the short length (approximately 300 feet) and multiple turn lanes in both directions of travel, the daily capacity of this segment was increased to reflect the capacity for a six-lane Major Arterial.

As shown in Table 11, all of the study roadway segments are forecast to operate at acceptable levels of service (LOS D or better) under existing plus cumulative conditions without the SR-78 / Nordahl Road interchange improvements, without and with the proposed project.

Existing Plus Cumulative Level of Service Analysis – With SR-78 / Nordahl Road Interchange Improvements

The existing plus cumulative level of service analysis with the planned SR-78 / Nordahl Road interchange improvements assumes the completion of the Nordahl Road bridge replacement and interchange project. The improvements include a third lane in each direction of travel on Nordahl Road between Montiel Road and Mission Road to serve left-turning traffic at the on-ramps, longer turn bay storage at the ramp intersections, and an additional eastbound turn lane at the Nordahl Road / SR-78 Eastbound Ramps intersection (off-ramp). In addition, the City is planning to improve the signal interconnection along Nordahl Road and is considering implementation of adaptive signal control on Nordahl Road in the vicinity of the SR-78 interchange.

The existing plus cumulative conditions intersection lane geometries with the SR-78 / Nordahl Road interchange improvements are illustrated in Exhibit 13.

Table 12 summarizes the existing plus cumulative peak hour intersection LOS with the SR-78 / Nordahl Road interchange improvements, without and with the proposed project. Detailed HCM calculation sheets are contained in Appendix H and I for the without and with project scenarios, respectively.

Table 12 Existing Plus Cumulative Peak Hour Intersection Conditions With SR-78 / Nordahl Road Interchange Improvements

Change in Without Project With Project Delay (1) Study Intersection AM Delay PM Delay AM Delay PM Delay AM PM – LOS (1) – LOS (1) – LOS (1) – LOS (1) Nordahl Road / SR-78 Westbound Ramps 30.1 – C 52.3 – D 30.7 – C 53.7 – D 0.6 1.4

Nordahl Road / SR-78 Eastbound Ramps 27.8 – C 46.2 – D 28.0 – C 47.3 – D 0.2 1.1 Note: Deficient intersection operation shown in bold. Change in delay shown in bold indicates a project significant impact. (1) Seconds of delay per vehicle.

As shown in Table 12, under existing plus cumulative conditions with the SR-78 / Nordahl Road interchange improvements, the Nordahl Road / SR-78 ramp intersections are forecast to operate at acceptable levels of service (LOS D or better) both without and with the proposed project.

Table 13 presents the results of the existing plus cumulative conditions roadway segment level of service analysis with the SR-78 / Nordahl Road interchange improvements, without and with the proposed project.

Table 13 Existing Plus Cumulative Daily Roadway Segment Conditions With SR-78 / Nordahl Road Interchange Improvements

As shown in Table 13, all of the study roadway segments are forecast to operate at acceptable levels of service (LOS D or better) under existing plus cumulative conditions with the SR-78 / Nordahl Road interchange improvements, without and with the proposed project.

SIGNIFICANT IMPACTS AND MITIGATION

A project-related significant impact is forecast to occur if:

1. The addition of project-generated traffic results in a change from an acceptable (LOS D or better) to a deficient (LOS E or worse) level of service at an intersection or along a roadway segment; OR

2. At a location operating at a deficient level of service without the project, the addition of project traffic results in an increase in delay of greater than 2.0 seconds at an intersection or an increase in v/c ratio of greater than 0.02 on a roadway segment.

Intersection and Roadway Segment Significant Impacts and Mitigation

The results of the analysis under existing plus project conditions show that all of the study intersections and roadway segments are forecast to operate at acceptable levels of service (LOS D or better) both without and with the proposed project.

The analysis results under existing plus cumulative conditions show that the addition of traffic from the 15 cumulative projects listed in Table 9 result in deficient intersection operations during the p.m. peak hour at both of the Nordahl Road / SR-78 ramp intersections if the planned SR-78 / Nordahl Road interchange improvements are not constructed.

28 Under existing plus cumulative conditions without the planned SR-78 / Nordahl Road interchange improvements, the two Nordahl Road / SR-78 ramp intersections are forecast to operate at a deficient level of service (LOS E or worse) both without and with the proposed project. The increase in delay as a result of the addition of project-generated traffic at the deficient intersection of Nordahl Road / SR-78 Eastbound Ramps is above the threshold of significance (2.0 seconds); therefore, the proposed project is forecast to result in a significant impact.

The analysis results under existing plus cumulative conditions with the SR-78 / Nordahl Road interchange improvements show that all study intersections and roadway segments are forecast to operate at acceptable levels of service.

The Cities of San Marcos and Escondido, Caltrans, and SANDAG are contributing to fund the planned SR-78 / Nordahl bridge replacement and interchange improvements. To mitigate the significant impact at the Nordahl Road / SR-78 Eastbound Ramps intersection under existing plus cumulative plus project conditions, the applicant / developer for the proposed development will be required to pay Public Facilities Fees as established by the latest adopted Public Facilities Fee Resolution.

CALTRANS ILV ANALYSIS

The California Department of Transportation (Caltrans) requires freeway ramp intersections to be evaluated using the Intersection Lane Volumes (ILV) methodology for evaluating intersection performance. This methodology considers the signal phasing, volumes and intersection capacity. The thresholds for intersection performance are summarized in Table 14.

Table 14 ILV Methodology Performance Criteria Critical Volume Through Classification Description Intersection Slight, but considerable delays Less than 1,200 Stable Flow possible. 1,200 to 1,500 Unstable Flow Considerable delays expected to occur. Stop and go conditions with severe Greater than 1,500 Capacity delay and heavy congestion.

The results of the Caltrans ILV analysis for all study scenarios are summarized in Table 15. ILV analysis worksheets are provided in Appendix J.

As shown in Table 15, under existing conditions both without and with the project, all ramp study intersections operate under the capacity threshold of 1,500 vehicles per hour.

Table 15 Caltrans ILV Analysis Summary

Without Project With Project Intersection AM Peak PM Peak AM Peak PM Peak Flow Operations Flow Operations Flow Operations Flow Operations Existing Conditions Nordahl Road / SR-78 Westbound Ramps 682 Stable 987 Stable 702 Stable 1,001 Stable Nordahl Road / SR-78 Eastbound Ramps 786 Stable 951 Stable 808 Stable 971 Stable Existing Plus Cumulative Conditions – Without SR-78 / Nordahl Road Interchange Improvements Nordahl Road / SR-78 Westbound Ramps 900 Stable 1,284 Unstable 920 Stable 1,297 Unstable Nordahl Road / SR-78 Eastbound Ramps 1,231 Unstable 1,374 Unstable 1,254 Unstable 1,392 Unstable Existing Plus Cumulative Conditions – With SR-78 / Nordahl Road Interchange Improvements Nordahl Road / SR-78 Westbound Ramps 900 Stable 1,284 Unstable 920 Stable 1,297 Unstable Nordahl Road / SR-78 Eastbound Ramps 1,030 Stable 1,350 Unstable 1,050 Stable 1,359 Unstable

Under existing plus cumulative conditions, the two study ramp intersections are forecast to perform under “Unstable” operations during the peak hours without and with the proposed project. The planned SR-78 / Nordahl Road interchange improvements would improve intersection performance to “Stable” operations at both intersections during the a.m. peak hour, without and with the proposed project. The two study ramp intersections would continue performing under “Unstable” operations during the p.m. peak hour with the SR-78 / Nordahl Road interchange improvements, under existing plus cumulative conditions without and with the project.

It must be noted that the Caltrans ILV analysis methodology does not include project significance thresholds, and so cannot be used to determine project impacts.

CONSTRUCTION TRAFFIC ANALYSIS

The construction contractor for the Costco Wholesale Specific Plan project provided detailed information on demolition, earthwork and paving truck hauling activities. These activities would be phased and so would not overlap. The construction schedule to complete the project is approximately 15 months. Table 16 summarizes the details of the construction truck hauling activity associated with the proposed project. Table 16 assumes the truck hauling activity would occur between the hours of 7:00 a.m. and 4:00 p.m., and it is assumed that truck trips per hour would remain constant throughout the day.

Table 16 Summary of Construction Truck Hauling Activity

Demolition Vehicle Vehicle Total Total Loads Loads Vehicle Duration Trips Miles Vehicle Vehicle Phase Loads Per Per Trips (Days) Per Per Day Trips Miles Day Hour Per Day Hour (1) (2) (3) Phase 1 450 13 35 4 70 8 2,100 910 27,300

Phase 2 77 3 26 3 52 6 1,560 156 4,680

Phase 3-4 614 18 34 4 68 8 2,040 1,224 36,720

Phase 5 262 8 33 4 66 8 1,980 528 15,840

Phase 6 103 3 35 4 70 8 2,100 210 6,300 Total Demo 1,506 45 3,028 90,840 Earthwork

Phase 1 4,072 28 150 17 300 34 3,000 8,400 84,000 Paving Phase 1 1,500 10 150 17 300 34 6,000 3,000 60,000

Combined 7,078 83 14,428 234,840 Total (1) It is assumed that truck traffic associated with demolition activities would travel 30 miles each way to and from the County landfill. (2) It is assumed that truck traffic associated with earthwork activities would travel 10 miles each way to and from another construction site in the region. (3) It is assumed that truck traffic associated with paving activities would travel 20 miles each way to and from Vulcan’s Carroll Canyon Plant.

Table 16 shows that demolition activities associated with the proposed project would be completed in six phases over a period of 45 days. The loads would be carried out by five trucks per day, with up to approximately 35 loads occurring each day. The demolition activities would generate up to 70 truck trips per day, with up to 8 trips occurring per hour. The demolition materials will be hauled to the County landfill, located approximately 30 miles from the project site. The trucks hauling the demolition materials are estimated to travel up to a total of 2,100 miles per day, and a total of 90,840 vehicle miles are estimated for the duration of the demolition activities.

As shown in Table 16, the earthwork activities would be completed in one phase over a period of 28 days. The loads would be carried out by 20 trucks per day, with approximately 150 loads occurring each day. The earthwork activities would generate up to 300 truck trips per day, with up to 34 trips occurring per hour. The earthwork materials will be hauled to another construction site in the region, with the location depending on which development will need earthwork at that time. It is assumed that the trucks hauling the earthwork materials would travel up to 10 miles each way to and from another construction site. Trucks associated with the earthwork activities are estimated to travel a total of 3,000 miles per day, and a total of 84,000 vehicle miles are estimated for the duration of the earthwork activities.

Table 16 shows that the paving activities would be completed in one phase over a period of 10 days. The loads would be carried out by 20 trucks per day, with approximately 150 loads occurring each day. The paving activities would generate up to 300 truck trips per day, with up to 34 trips occurring per hour. Paving materials will be brought to the project site from Vulcan’s Carroll Canyon Plant located approximately 20 miles from the project site. Trucks associated with the paving activities are estimated to travel a total of 6,000 miles per day, and a total of 60,000 vehicle miles are estimated for the duration of the paving activities.

It is assumed that most of the truck traffic associated with the construction activities described above would travel between the project site and the SR-78 / Nordahl Road interchange. Truck traffic associated with the demolition activities would travel on SR-78 and I-15 to and from the County landfill. It is not known at this time where earthwork materials will be hauled to, but it is assumed that trucks would use SR-78 to travel to and from this other site. Truck traffic associated with the paving activities would travel on SR-78 and I-15 to and from Vulcan’s Carroll Canyon Plant.

Construction truck traffic impacts to the Nordahl Road / SR-78 ramp intersections are expected to be less than significant during the traffic peak hours. A maximum of 34 truck trips per hour are estimated to occur throughout the day. To reduce the potential for construction traffic impacts, it is recommended that a Transportation Management Plan (TMP) be prepared and approved by the City, and that monitoring occurs during the construction period.

SUMMARY AND CONCLUSIONS

This study analyzes the forecast traffic impact of the proposed Costco Wholesale Specific Plan project, located on a 16.3-acre site that includes the existing Costco store on the west side of the Nordahl Marketplace shopping center, west of Nordahl Road and north of SR-78 in the City of San Marcos. The proposed project consists of replacing the existing 134,818 square-foot Costco warehouse building and 49,069 square-foot Harley Davidson building with a new 148,233 Costco warehouse building, a satellite fuel station with 16 pumps and a satellite car wash. As required by the City of San Marcos, this traffic impact study has been prepared in accordance with the City’s General Plan Circulation Element and SANTEC/ITE traffic study guidelines. A total of five intersections and three roadway segments are included in the study area.

This traffic impact analysis evaluated the following study scenarios:

• Existing Conditions • Existing Plus Project Conditions • Existing Plus Cumulative Conditions Without Project (without and with SR-78 / Nordahl Road interchange improvements) • Existing Plus Cumulative Conditions With Project (without and with SR-78 / Nordahl Road interchange improvements)

The analysis results under existing conditions show that the all study intersections and roadway segments currently operate at acceptable levels of service (LOS D or better), and are forecast to continue operating at acceptable LOS with the addition of project-generated traffic to existing traffic volumes.

The results of the analysis under existing plus cumulative conditions show that the addition of traffic from the 15 cumulative projects listed in Table 8 result in deficient intersection operations during the p.m. peak hour at both of the Nordahl Road / SR-78 ramp intersections if the planned SR-78 / Nordahl Road interchange improvements are not constructed.

Under existing plus cumulative conditions without the planned SR-78 / Nordahl Road interchange improvements, the two Nordahl Road / SR-78 ramp intersections are forecast to operate at a deficient level of service (LOS E or worse) both without and with the proposed project. The increase in delay as a result of the addition of project-generated traffic at the deficient intersection of Nordahl Road / SR-78 Eastbound Ramps is above the threshold of significance (2.0 seconds); therefore, the proposed project is forecast to result in a significant impact.

The results of the roadway segment analysis under existing plus cumulative conditions without the SR-78 / Nordahl Road interchange improvements show that all of the study roadway segments are forecast to operate at acceptable levels of service (LOS D or better) without and with the proposed project.

33 The analysis results under existing plus cumulative conditions with the SR-78 / Nordahl Road interchange improvements show that all study intersections and roadway segments are forecast to operate at acceptable levels of service without and with the proposed project.

The results of the Caltrans ILV analysis show that all ramp study intersections currently operate under the capacity threshold of 1,500 vehicles per hour. Under existing plus cumulative conditions, the two study ramp intersections are forecast to perform under “Unstable” operations during the peak hours without and with the proposed project. The planned SR-78 / Nordahl Road interchange improvements would improve intersection performance to “Stable” operations at both intersections during the a.m. peak hour, without and with the proposed project. The two study ramp intersections would continue performing under “Unstable” operations during the p.m. peak hour with the SR-78 / Nordahl Road interchange improvements, under existing plus cumulative conditions without and with the project.

It must be noted that the Caltrans ILV analysis methodology does not include project significance thresholds, and so cannot be used to determine project impacts.