New Seward Highway Rabbit Creek Road to 36Th Avenue

New Seward Highway Rabbit Creek Road to 36th Avenue

Environmental Assessment Volume II, Appendixes Project Number: FRAF-CA-MGS-NH-0A3-1(27)/52503

U.S. Department of Transportation, Alaska Division of the Federal Highway Administration, and the Alaska Department of Transportation and Public Facilities

July 2006

APPENDIX E Noise Analysis

ANC/TP5047.DOC/050810013

New Seward Highway Rabbit Creek to 36th Avenue

Project No. FRAF-CA-MGS-NH-0A3-1(27)/52503

Noise Analysis

Prepared for Alaska Department of Transportation and Public Facilities

June 2006

301 West Northern Lights Boulevard, Suite 601 Anchorage, Alaska 99503-2662 (907) 278-2551

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001 Contents

Section Page Abbreviations...... vii Executive Summary...... ES-1 1 Introduction ...... 1 1.1 Project Background and Purpose ...... 1 1.2 Study Purpose ...... 2 2 Fundamentals of Traffic Noise...... 9 3 FHWA and DOT&PF Criteria for Noise Abatement...... 13 4 Methodology...... 15 5 Existing Noise Environment ...... 17 5.1 Setting...... 17 5.2 Existing Land Use...... 17 5.3 Measured Traffic Noise Levels ...... 18 5.4 Existing Noise Levels for Peak-Hour Traffic ...... 32 6 Future Noise Impacts...... 39 6.1 Traffic Noise Impacts ...... 39 7 Mitigation...... 47 7.1 Traffic Noise Mitigation...... 47 7.2 Noise Barrier Analysis ...... 48 8 Construction Noise ...... 69 9 Conclusions...... 71 10 List of Preparers...... 73 11 References...... 75

Attachments A Acoustical Terminology B Alternative Descriptions C Onsite Noise Level Measurement Data D Traffic Data Summary E Noise Abatement Checklists

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE III ANC\053120001 CONTENTS, CONTINUED

Table Page 1 Measurements of Typical Noise Levels...... 10 2 Federal Highway Administration Noise Abatement Criteria Adjusted for DOT&PF Noise Abatement Policy ...... 13 3 Summary of Measured Traffic Noise Levels (June 11-14, 2003) ...... 29 4 Comparison of Measured and Predicted Traffic Noise Levels ...... 31 5 Applied Reduction Factors...... 31 6 Summary of Modeled Existing Noise Levels and Impact Assessment ...... 32 7 Comparison of Future Noise Impacts...... 40 8 Barrier B1 Design...... 58 9 Barrier B1 Noise Reduction...... 58 10 Barrier B2 Design...... 60 11 Barrier B2 Noise Reduction...... 60 12 Barrier B6 Design...... 62 13 Barrier B6 Noise Reduction – Alternative 1, Option 1...... 62 14 Barrier B6 Noise Reduction – Alternative 1, Option 2...... 62 15 Barrier B6 Noise Reduction – Alternative 2, Option 1...... 63 16 Barrier B6 Noise Reduction – Alternative 2, Option 2...... 63 17 Barrier B7-8 Noise Reduction—Alternative 1, Option 1 ...... 64 18 Barrier B7-8 Noise Reduction—Alternative 1, Option 2 ...... 64 19 Barrier B7-8 Noise Reduction—Alternative 2, Option 1 ...... 65 20 Barrier B7-8 Noise Reduction—Alternative 2, Option 2 ...... 65 21 Barrier B7-8 Noise Reduction—Alternative 2, Option 1 ...... 66 22 Barrier B9 Noise Reduction—Alternative 1, Option 1...... 66 23 Barrier B9 Noise Reduction—Alternative 1, Option 2...... 66 24 Barrier B9 Noise Reduction—Alternative 2, Option 1...... 67 25 Barrier B9 Noise Reduction—Alternative 2, Option 2...... 67 26 Barrier B10 Noise Reduction—Alternative 1, Option 1...... 68 27 Construction Equipment Noise ...... 69

Figure Page 1 Study Area...... 3 2a Existing Corridor...... 5 2b Existing Corridor...... 7 3 Zoning Districts and Subareas in Study Area ...... 19 4 Noise Receptor Locations ...... 21 5 Noise Receptor Locations ...... 23 6 Noise Receptor Locations ...... 25 7 Noise Receptor Locations ...... 27 8 Noise Receptor and Proposed Noise Barrier Locations ...... 49 9 Noise Receptor and Proposed Noise Barrier Locations ...... 51 10 Noise Receptor and Proposed Noise Barrier Locations ...... 53 11 Noise Receptor and Proposed Noise Barrier Locations ...... 55

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Abbreviations

ANSI American National Standards Institute CFR Code of Federal Regulations dB decibel dBA A-weighted decibel DD doubled distance DOT&PF Alaska Department of Transportation and Public Facilities

°F degrees Fahrenheit FHWA Federal Highway Administration Hz Hertz kHz kilohertz

Ldn day-night noise level

Leq equivalent steady-state noise level, which in a stated period of time would contain the same acoustical energy as the time-varying noise level during the same period

Leq(h) energy-average of the A-weighted noise levels occurring during a 1-hour period LRTP Long Range Transportation Plan

μPa micropascal MOA Municipality of Anchorage NAC noise abatement criteria (or criterion) PER Preliminary Engineering Report PLI public lands and institutions TNM Traffic Noise Model

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE V ANC\053120001

Executive Summary

This report describes the methods and findings for a noise analysis conducted for the New Seward Highway, Rabbit Creek to 36th Avenue, environmental document. The purpose of this analysis is to evaluate existing and projected future traffic noise levels at noise-sensitive locations along the project corridor, ascertain the need for traffic noise abatement, and determine the feasibility and reasonableness of constructing noise barriers, if necessary. A total of 19 field-monitored receivers and an additional 103 residential and 26 commercial receivers were modeled to represent all noise-sensitive land uses along the project corridor. As a result of this traffic noise analysis, the following conclusions are presented:

• Noise levels for existing peak-hour traffic approach or exceed the Federal Highway Administration and the Alaska Department of Transportation and Public Facilities (DOT&PF) noise abatement criteria (NAC) at 75 of the identified noise-sensitive receivers. Noise levels for peak-hour traffic approach or exceed the NAC at 116 locations under the future (2035) No-Build Alternative. The NAC are exceeded at 122 locations under Build Alternative 1, Option 1 and Option 2, and Build Alternative 2, Option 1, and at 123 locations under future Build Alternative 2, Option 2.

• The calculated noise levels show that future increases above existing noise levels would be up to 4 A-weighted decibels (dBA) under the No-Build Alternative and vary from 4 dBA below existing to 11 dBA above existing under the build alternatives. At some locations, the increases in future noise levels would exceed the DOT&PF substantial increase threshold of 10 dBA or more.

• Six noise barriers were considered to reduce future traffic noise levels in noise-sensitive areas by a minimum of 5 dBA. A cost reasonableness and feasibility analysis was used to determine which barriers would be recommended. Barriers B1, B2, B6, B7-8, B9 and B10 meet the DOT&PF cost reasonableness criterion of $25,000 per benefited receiver and reduce future noise levels for peak-hour traffic related to the proposed project by 5 dBA or more. These barriers are shown to be both feasible and reasonable; therefore, they are recommended for construction. For the purposes of the EA, the affected public is assumed to desire noise abatement. The conclusions and recommendations provided are based on preliminary design data and current policy and conditions. These recommendations will be reevaluated after the formal comment period and during the final design of each phase of construction.

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SECTION 1 Introduction

1.1 Project Background and Purpose The Alaska Department of Transportation and Public Facilities (DOT&PF) and the Federal Highway Administration (FHWA) are proposing improvements along New Seward Highway between Rabbit Creek Road and 36th Avenue. Figure 1 is a vicinity map showing the project location. The proposed roadway improvements begin at O’Malley Road and include both widening and realigning the roadway. The proposed action would provide additional capacity and connectivity, as well as enhance safety. The purposes of the New Seward Highway, Rabbit Creek Road to 36th Avenue, project are as follows:

• Accommodate 2035 travel demand

• Improve traffic circulation by linking east-west road segments that are currently separated by the New Seward Highway corridor

• Provide more transportation choices, including bicycle and pedestrian facilities

• Improve transportation safety by bringing New Seward Highway up to current roadway design standards and reducing congestion The New Seward Highway is the primary north-south traffic carrier for the Anchorage Bowl. The freeway is centrally located and provides important transportation functions for Southcentral Alaska residents, commercial goods movement, and visitors. The existing highway corridor is a four-lane, controlled-access facility from Rabbit Creek to 36th Avenue. During the morning commute period, traffic volume increases, travel speed reduces, and traffic often diverts to frontage roads as travelers make their way to midtown and downtown Anchorage employment centers. During evening peak hours, the traffic exiting at ramps often backs up onto the freeway, creating potentially unsafe conditions. The constant stop-and-start, congested traffic flow common during the peak periods is a situation that jeopardizes the safety of travelers. The Anchorage Bowl 2025 Long-Range Transportation Plan (LRTP) (Municipality of Anchorage [MOA], DOT&PF, and Anchorage Metropolitan Area Transportation Solutions, 2005) indicates substantial population growth and economic development in the region served by the New Seward Highway corridor and study area, conditions expected to exacerbate the existing congestion problem. See Figures 2a and 2b for illustrations of the existing New Seward Highway. The two proposed build alternatives each incorporate two options. Both alternatives would provide roadway expansion with grade separations at major cross streets. Build Alternative 1 would offer interchange improvements to Tudor Road. Build Alternative 2 would provide a full-diamond interchange at International Airport Road. See Attachment B for descriptions of the alternatives and their respective options.

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 1 ANC\053120001 INTRODUCTION

1.2 Study Purpose The purpose of this analysis is to assess current and future peak-hour traffic noise exposure at noise-sensitive locations along New Seward Highway from Rabbit Creek to 36th Avenue, evaluate noise abatement measures for areas where applicable noise abatement criteria (NAC) are exceeded, and recommend noise abatement measures where such measures are deemed to be feasible and reasonable in accordance with DOT&PF policy.

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SECTION 2 Fundamentals of Traffic Noise

Sound pressure can be measured in units of micronewtons per square meter, called micropascals (μPa). One μPa is approximately one-hundred-billionth of the normal atmospheric pressure. The pressure of a very loud sound may be 200 million μPa, or 10 million times the pressure of the weakest audible sound (20 μPa). Expressing sound levels in terms of μPa would be very cumbersome because of this wide range. Therefore, sound pressure levels are described in logarithmic units of ratios of actual sound pressures to a reference pressure squared. These units are called bels, named after Alexander G. Bell. To provide a finer resolution, a bel is subdivided into decibels (tenth of a bel), abbreviated dB. Attachment A provides a description of the acoustical terminology used in this report. Unless otherwise stated, all sound levels reported are in A-weighted decibels (dBA). A- weighted decibels are measured with a sound-level meter having the metering characteristics and a frequency weighting specified in the American National Standards Institute (ANSI) Specification for Sound Level Meters, ANSI S 1.4–1983. The A-weighting de-emphasizes lower frequency sounds below 1,000 Hertz (Hz) (1 kilohertz [kHz]) and higher frequency sounds above 4 kHz. It emphasizes sounds between 1 kHz and 4 kHz. A- weighting is the most generally used measure for traffic and environmental noise throughout the world. Most community noise standards utilize A-weighting because it provides a high degree of correlation with human annoyance and health effects. Table 1 shows the relative A-weighted sound levels or noise levels of common sounds measured in the environment and in industry. The actual impact of noise is not a function of loudness alone. The time of day during which noise occurs and the duration of the noise are also important. In addition, most noise that lasts for more than a few seconds is variable in its intensity. Consequently, a variety of noise descriptors have been used, such as L10, L50, and Ldn. The noise descriptor used for this study is Leq, the equivalent steady-state noise level, which in a stated period of time would contain the same acoustical energy as the time-varying noise level during the same period. The Leq(h) is the energy-average of the A-weighted noise levels occurring during a 1-hour period, in decibels (a 1-hour Leq). From the source to the receiver, noise changes both in level and frequency spectrum. The most obvious is the decrease in noise as the distance from the source increases. The manner in which noise reduces with distance depends on the following important factors:

• Geometric spreading from point and line sources • Ground absorption • Atmospheric effects and refraction • Shielding by natural and manmade features, noise barriers, diffraction, and reflection

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 9 ANC\053120001 FUNDAMENTALS OF TRAFFIC NOISE

TABLE 1 Measurements of Typical Noise Levels

Noise Source A-Weighted Noise level Subjective at a Given Distance (decibels) Impression

Military jet takeoff with after-burner (50 feet) 140

Civil defense siren (100 feet) 130

Jet takeoff (200 feet) 120 Threshold of pain

Loud rock music 110

Pile driver (50 feet) 100 Very loud

Diesel truck (150 feet) 90

Garbage disposal (3 feet) 80

Vacuum cleaner (10 feet) 70 Moderately loud

Normal conversation (3 feet) 60

Light traffic (100 feet); rainfall 50

Bird calls (distant) 40 Quiet

Soft whisper (5 feet); rustling leaves 30

Library 20

Normal breathing 10

0-1 Threshold of hearing

Sounds from a small localized source (approximating a “point” source) radiates uniformly outwards as it travels away from the source in a spherical pattern. The noise level decreases or drops off at a rate of 6 dBA for each doubling of the distance (DD). Highway traffic noise is not a single, stationary point source of sound, however. The movement of the vehicles makes the source of the sound appear to emanate from a line (line source) rather than a point when viewed over some time interval. Generally, noise levels from a highway decrease at rates of 3 dBA to 4.5 dBA for each doubling of distance from the highway, depending on the type of terrain between the highway and receivers. Two site types are currently used in traffic noise models:

• Hard sites–Sites with a reflective surface between the source and the receiver, such as parking lots or smooth bodies of water. No excess ground attenuation is assumed for these sites, and the changes in noise levels with distance (drop-off rate) are simply the geometric spreading of the line source or 3 dBA/DD (6dBA/DD for a point source).

• Soft sites–Sites with an absorptive ground surface, such as soft dirt, grass, or scattered brush and trees. An excess ground attenuation value of 1.5 dBA/DD is normally

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assumed. When added to the geometric spreading, this value results in an overall drop- off rate of 4.5 dBA/DD for a line source (7.5 dBA/DD for a point source). Research by the California Department of Transportation and others has shown that atmospheric condition can have a profound effect on noise levels within 200 feet of a highway. Wind has shown to be the single most important meteorological factor within approximately 500 feet, and vertical air temperature gradients are more important over longer distances. Other factors, such as humidity and turbulence, also have significant effects. Changes in noise levels are perceived as follows:

• 3–dBA change is barely perceptible. • 5–dBA change is readily perceptible. • 10–dBA change is perceived as a doubling or halving of noise.

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SECTION 3 FHWA and DOT&PF Criteria for Noise Abatement

The criteria for evaluating noise impacts used in this report are contained in Title 23, Part 772, Code of Federal Regulations (CFR), Procedures for Abatement of Highway Traffic Noise and Construction Noise (FHWA, 1992), and the DOT&PF Noise Abatement Policy (1996). Table 2 summarizes the NAC established by DOT&PF in accordance with FHWA requirements.

TABLE 2 Federal Highway Administration Noise Abatement Criteria Adjusted for DOT&PF Noise Abatement Policy

Activity Noise Abatement Criteria (NAC), L hourly (dBA) Category eq Description of Land-Use Activity Category

A 55 Tracts of land for which serenity and quiet are of extraordinary (exterior) significance, and which serve an important public need. The preservation of serenity and quiet is essential if this land is to continue to serve its intended purpose. Such areas could include amphitheaters, particular parks or portions of parks, open spaces, or historic districts dedicated to or recognized by appropriate local officials for activities requiring special qualities of serenity and quiet.

B 65 Picnic areas, recreation areas, playgrounds, active sports areas, (exterior) and parks that are not included in Category A and residences, motels, hotels, public meeting rooms, schools, churches, libraries, and hospitals.

C 70 Developed lands, properties or activities not included in (exterior) Categories A and B above.

D – Undeveloped lands.

E 50 Residences, motels, hotels, public meeting rooms, schools, (interior) churches, libraries, hospitals, and auditoriums. Source: Federal Highway Administration, April 1992, 23 CFR 772, Procedures for Abatement of Highway Traffic Noise and Construction Noise.

Activity Category A applies to locations that serve an important public need in which local officials recognize the importance of maintaining quiet surroundings. No Activity Category A land uses were identified within the project study area. The Category B criterion in the FHWA and DOT&PF documents applies to residences, churches, schools, recreation areas, and similar use sites. As discussed in Section 5.2, Existing Land Use, Activity Category B land uses occur throughout the project corridor. The FHWA NAC for Category B land uses is 67 dBA Leq. The FHWA and DOT&PF consider a traffic noise impact to occur if predicted noise levels for peak-hour traffic approach or

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 13 ANC\053120001 FHWA AND DOT&PF CRITERIA FOR NOISE ABATEMENT

exceed the NAC. The DOT&PF defines “approach” as noise levels within 2 dBA of NAC, meaning 65 dBA for Activity Category B. Commercial and industrial land uses fall into Category C, for which the FHWA NAC is 72 dBA Leq. Because DOT& PF defines “approach” as within 2 dBA of the FHWA levels, the resulting DOT&PF criteria shown in Table 2 for Activity Category C is 70 dBA. DOT&PF policy does not provide noise abatement for Activity Category C, unless it is necessary to protect adjacent sensitive areas (land use Categories A and B). There are no criteria for undeveloped land (Category D), which is found intermittently along the corridor. The above-described noise level criteria are determined at the exterior use areas of structures during peak-hour noise conditions. Where there are no exterior activity areas or where exterior areas are shielded from the roadway so that there are no exterior impacts, the interior FHWA NAC (Category E) should be used. Polaris K-12 School and Aspen Apartments are among the Activity Category E land uses identified within the project study area. The DOT&PF Noise Abatement Policy (1996) defines “substantial” as an increase of 10 dBA over existing noise levels. In addition to the criterion noise levels described above, the FHWA and the DOT&PF consider a traffic noise impact to occur if predicted noise levels “substantially” exceed existing noise levels. Therefore, noise abatement features must be considered for the proposed project if predicted noise levels for the design year result in a noise level increase of 10 dBA or more above existing noise levels or predicted noise levels equal or exceed 65 dBA Leq for Category B land uses or 50 dBA interior noise levels where exterior use areas do not occur (Category E). DOT&PF policy does not provide noise abatement for Activity Category C or D.

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SECTION 4 Methodology

Existing and projected future (2035) traffic noise levels were evaluated by using the FHWA Traffic Noise Model (TNM), Version 2.1 (FHWA, 1998a, 1998b). TNM is the FHWA preferred method for highway traffic noise prediction. The FHWA TNM is based on reference energy emission levels for automobiles, medium trucks (two axles), heavy trucks (three or more axles), buses, and motorcycles with consideration given to vehicle volume, speed, roadway configuration, distance to the receiver, and the acoustical characteristics of the site. TNM was developed to predict hourly Leq values for free-flowing and interrupted-flow traffic conditions, and is generally considered to be accurate within +3 dBA. The model enables the user to account for the attenuation over or through rows of buildings and dense vegetation. TNM enables the user to input terrain elevation lines to account for shielding effects of natural terrain. The model also allows the user to specify various intervening ground types with different sound absorption qualities. The ground types available for use include soft and hard soil, snow- covered ground, water, and pavement. The noise model also allows for input of temperature and relative humidity to account for the atmospheric effects of these factors on noise propagation. On the basis of FHWA recommendation, the default temperature of 68 degrees Fahrenheit (°F) and a relative humidity of 50 percent are used in this analysis. Current tools do not offer analysis capabilities for the effects of other factors such as wind and atmospheric inversions. Therefore, similar to other noise studies of its kind, a no-wind condition is assumed for this noise analysis. In this study, traffic noise levels calculated by TNM are validated by using onsite traffic noise level measurement data and concurrent traffic counts obtained throughout the project corridor. (See Attachment C.) To model the roadways, receiver and barrier locations, and intervening topography within the project area, terrain information and roadway geometry data were obtained from the roadway design data used and/or created for the New Seward Highway Rabbit Creek Road to 36th Avenue Preliminary Engineering Report (PER) (CH2M HILL, 2004). Traffic volumes used for assessment of existing (20031) noise exposure and truck volumes, directional splits, and vehicle speeds used for both existing and future conditions were obtained from a traffic analysis completed as part of the New Seward Highway PER. Projected future (2035) peak hour traffic volumes were derived by using TransCAD software, Version 4.5. Attachment D lists all of the traffic assumptions used as inputs to the TNM.

1 There is approximately a 1 percent growth in traffic volumes between 2003 and 2005. This small increase does not result in a distinguishable difference in traffic noise levels.

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 15 ANC\053120001 METHODOLOGY

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SECTION 5 Existing Noise Environment

5.1 Setting Vehicular traffic on New Seward Highway is the dominant source of environmental noise at noise-sensitive areas in the southern half of the study area between Rabbit Creek Road and Dimond Boulevard. Other environmental noise sources include occasional aircraft flights and some traffic on local collector streets off the frontage roads. Vehicular traffic on New Seward Highway is also the dominant source of noise in the study area north of Dimond Boulevard; however, intermittent commercial jet departures from Ted Stevens Anchorage International Airport also are prominent sources of noise. Throughout most of the project corridor, traffic on frontage roads and other local roadways is an insignificant contributor to overall noise exposure.

5.2 Existing Land Use Field investigation revealed in general that land uses in the project corridor were consistent with their zoning designations; however, some zoning designations include special limitations. In general, major shopping areas, an extensive retail network, and a light- industrial area lie west of the project corridor. The Dimond Boulevard area west of New Seward Highway is a major commercial center, and is the single largest development and retail freight destination in Anchorage. Another large commercial center lies in Midtown west of New Seward Highway around 36th Avenue, the northern terminus of the proposed project. These commercial centers attract consumers and generate commercial truck traffic through the project corridor. New Seward Highway is a major freight corridor and provides consumer access to commercial facilities. Property east of the project corridor is mainly residential, with some mixed-use development. An exception is in the area east of Dimond Boulevard where commercial development has increased significantly during the past few years. The southern end of the project corridor primarily consists of single-family residential units. As New Seward Highway progresses north crossing Huffman Road, multifamily residential units become visible, followed by a public golf course and large tracts of public lands and institutions (PLI) east of the highway. At O’Malley Road, the corridor passes through more multifamily residential areas, including the Southwood Manor Trailer Court east of the highway south of 92nd Avenue. A transition to retail and light-industrial centers is apparent as the corridor approaches Dimond Boulevard. From this area north, more mixed-use development is spread along the corridor, with small pockets of PLI zones. The corridor’s northern end is mostly single-family and multifamily residential areas to the east, with both office and retail commercial development dominating the west side of the corridor. See Figure 3 for a graphic of the existing land use surrounding New Seward Highway.

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 17 ANC\053120001 EXISTING NOISE ENVIRONMENT

5.3 Measured Traffic Noise Levels Traffic noise levels and concurrent traffic counts were measured at the exterior areas of representative residential locations in the study area and next to New Seward Highway between June 11 and June 13, 2003. See Attachment C for data on onsite noise-level measurement. The purposes of the noise level measurements were to document existing traffic noise levels and validate the use of the TNM to predict peak-hour traffic noise exposure. The study area was closely inspected to create an accurate model of the roadway and receiver locations. During the field inspection, site-specific features that could affect the acoustical conditions at each location (such as existing terrain features, building structures, existing barriers, intervening ground types, and roadway and receiver elevations) were noted. Measurement equipment consisted of a Larson Davis 824 system sound level meter. A Larson Davis CAL-200 acoustical calibrator was used for calibration of the microphone to ensure the accuracy of the measurements. All equipment complied with the requirements of ANSI and the International Electrotechnical Commission for precision sound-level measurement instrumentation. At the time the measurements were taken, the weather was partly cloudy to clear skies, slight winds (varying between calm to 5 miles per hour), and temperatures ranged between 60 ºF and 75ºF for the duration of the measurements. The roadway pavement was dry. Measurements were not restricted to peak hour periods. Figures 4 through 7 depict the location of existing barriers and the 19 noise monitoring locations. The noise monitoring locations were selected because they were representative of the noise-sensitive areas in the study area. The three-dimensional coordinates of each location were determined by using existing topographic data. The traffic noise measurements are summarized in Table 3.

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EXISTING NOISE ENVIRONMENT

TABLE 3 Summary of Measured Traffic Noise Levels (June 11–14, 2003)

Noise Level (dBA) Monitoring Location Land Use Location Description Leq Lmin Lmax

M1 Residential 14305 Lake Otis Parkway 56.6 45.2 68.7

M2 Residential 14210 Specking Avenue between 52.9 42.0 61.1 East 142nd and East 144th avenues

M3 Residential 13800 Specking Avenue north of 65.2 51.2 75.5 DeArmoun Road

M4 School Rabbit Creek Elementary School, 66.7 48.0 68.5 west end of soccer field

M51, 2 Residential/ East side of Hamilton Park, next to 65.9 46.8 71.0 Park children’s play area

M62 Residential Home at northeast corner of 60.0 47.4 72.9 Steeple and Brayton Drives (frontage road)

M72 Residential Between 12661 and 12670 Tanada 57.3 48.9 63.1 Circle, end of cul-de-sac

M8 Residential 1321 Klatt Road, end of cul-de-sac 62.7 50.5 70.6

M9 Residential Eagle Crest Apartments between 65.8 58.9 71.2 Huffman and O’Malley roads

M10 Residential Lawn area between 1661 and 1671 63.1 57.0 67.3 Elcadore Drive

M11 Residential 10320 Thuja Circle, backyard 65.4 54.9 71.2 facing New Seward Highway (Cedar Hollow Subdivision)

M12 Mobile Between mobile homes at 401 and 61.7 54.9 69.7 Homes 496 Jody Circle

M13 Residential Near 1270 Surrey Circle, multi- and 57.2 51.8 62.5 single-family homes west of New Seward Highway

M142 Mobile Between mobile homes at 103 and 60.9 54.2 67.8 Homes 105 Gross Circle, behind noise barrier

M15 Residential New single-family homes east of 64.3 53.1 73.7 New Seward Highway, south of Dimond Boulevard

M16 Residential Alpine Apartments, near Building 65.5 59.9 71.7 5310

M17 Residential 4901 Becharof Street, east of New 68.7 61.5 76.4 Seward Highway

M18 Residential 4554 Homer Drive, near the 62.6 57.8 70.0 southbound Tudor Road on-ramp

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TABLE 3 Summary of Measured Traffic Noise Levels (June 11–14, 2003)

Noise Level (dBA) Monitoring Location Land Use Location Description Leq Lmin Lmax

M19 Residential 3919 Helvetia Drive, front yard of 64.3 56.3 68.6 home Notes: 1 Results at M5 were elevated by aircraft over flights 2 Monitoring locations protected by existing noise barriers Leq: Equivalent average noise level for the measurement period Lmin: Minimum noise level for the measurement period Lmax: Maximum noise level during the measurement period

One step during noise modeling includes an evaluation of agreement between the noise levels measured in the field and those calculated by the noise model. This evaluation serves to calibrate the model, as represented in the “Difference” column in Table 4. A positive (+) difference indicates that noise levels measured in the field are lower than those predicted by the computer model. A negative (-) difference shows that measured noise levels are greater than predicted noise levels. Comparison of measured noise levels to those predicted by TNM show that at most locations the difference between measured and predicted noise levels are within ±2 dBA. For those cases, model results were used without adjustment to predict peak-hour noise levels. At a few locations, modeled noise levels differed from measured noise levels by 3 to 6 dBA. As seen in Table 4, the predicted noise levels at locations M5 and M8 were approximately 6 dBA and 5 dBA, respectively, below the noise levels measured in the field. This difference is most likely due to contribution of noise from other sources such as aircraft, or construction while measurements were taken in the field. Therefore, the TNM prediction will be used without adjustment. At monitoring locations M12, M13, M17 and M18 predicted noise levels were greater than those measured in the field from 3 to 6 dBA. In these cases, site-specific environmental factors such as variable terrain, ground absorption, or tree cover prevent the model from accurately predicting noise; therefore, a noise level reduction will be applied to the predicted values at each location. Table 5 lists the noise level reductions applied at each location.

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TABLE 4 Comparison of Measured and Predicted Traffic Noise Levels

Monitoring Measured L Predicted L Location eq eq Difference M1 56.6 57.4 0.8 M2 52.9 54.0 1.1 M3 65.2 67.9 2.7 M4 66.7 65.2 -1.5 M5 65.9 60.3 -5.6 M6 60.0 57.1 -2.9 M7 57.3 57.9 0.6 M8 62.7 56.5 -6.2 M9 65.8 67.3 1.5 M10 63.1 65.8 -2.7 M11 65.4 67.1 1.7 M12 61.7 67.8 6.1 M13 57.2 61.3 -4.1 M14 60.9 59.5 -1.4 M15 64.3 64.6 0.3 M16 65.5 68.2 2.7 M17 68.7 71.8 3.1 M18 62.6 67.5 4.9 M19 64.3 67.2 2.9 Note: All results in A-weighted decibels, dBA.

TABLE 5 Applied Reduction Factors

Receiver Location Reduction Factor (dBA)

M12 -6

M13 -4

M17 -3

M18 -5

Several existing noise barriers are located along the New Seward Highway corridor to protect outdoor areas of residences from traffic noise. All of these existing barriers are south of Dimond Boulevard and shown in Figures 4 through 7. They are as follows:

• An existing property line wall is located in the northwest quadrant of New Seward Highway and DeArmoun Road. This wall is approximately 250 feet long.

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 31 ANC\053120001 EXISTING NOISE ENVIRONMENT

• A noise barrier, approximately 4,100 feet long, extends from the northern end of Bell’s Nursery, west of New Seward Highway, along the existing highway right-of-way to Huffman Road.

• East of New Seward Highway, a property line barrier is located in the northeast quadrant of DeArmoun Road and New Seward Highway. The barrier is approximately 400 feet long.

• A noise barrier located east of New Seward Highway begins just south of Tradewind Drive on the west side of Brayton Drive and extends north approximately 2,600 feet, ending south of Jennifer Lane.

• North of Huffman Road and west of New Seward Highway is an existing barrier approximately 600 feet long and beginning south of East Klatt Road.

5.4 Existing Noise Levels for Peak-Hour Traffic To calculate existing levels of peak-hour noise with the validated model in TNM, existing peak-hour traffic volumes, traffic speed, and percentages of automobiles and trucks were obtained from a traffic analysis completed as part of the New Seward Highway PER. Table 6 presents calculated existing peak-hour noise levels and the applicable Noise Abatement Criteria (NAC). Level shown in bold font exceed the NAC.

TABLE 6 Summary of Modeled Existing Noise Levels and Impact Assessment (end of Section 5)

Map ID Land Use/ FHWA Classification Exist Level (dBA) Noise Abatement Criteria DeArmoun to Huffman M1 Residential/Category B 59 65 M2 Residential/Category B 58 65 M3 Residential/Category B 69 65 M4 Residential/Category B 69 65 M5 Residential/Category B 62 65 M6 Residential/Category B 61 65 M7 Residential/Category B 61 65 R1 Residential/Category B 60 65 R2 Residential/Category B 59 65 R3 Residential/Category B 62 65

32 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001 EXISTING NOISE ENVIRONMENT

TABLE 6 Summary of Modeled Existing Noise Levels and Impact Assessment (end of Section 5)

Map ID Land Use/ FHWA Classification Exist Level (dBA) Noise Abatement Criteria R4 Residential/Category B 61 65 R5 Residential/Category B 60 65 R6 Residential/Category B 63 65 R7 Residential/Category B 68 65 R8 Residential/Category B 63 65 R9 Residential/Category B 67 65 R10 Residential/Category B 62 65 R11 Residential/Category B 59 65 R12 Residential/Category B 59 65 R13 Residential/Category B 62 65 R14 Residential/Category B 60 65 R15 Residential/Category B 67 65 R16 Residential/Category B 63 65 Huffman to O'Malley M8 Residential/Category B 60 65 M9 Residential/Category B 69 65 R17 Residential/Category B 61 65 R18 Residential/Category B 64 65 R19 Residential/Category B 65 65 R20 Residential/Category B 64 65 C1 Commercial/Category C 42 70 C2 Commercial/Category C 65 70 C3 Commercial/Category C 61 70 C4 Commercial/Category C 61 70 O'Malley to Dimond M10 Residential/Category B 64 65 M11 Residential/Category B 69 65 M12 Residential/Category B 64 65 M13 Residential/Category B 59 65 M14 Residential/Category B 64 65 M15 Residential/Category B 67 65 R21 Residential/Category B 68 65 R22 Residential/Category B 64 65 R23 Residential/Category B 64 65 R24 Residential/Category B 63 65

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 33 ANC\053120001 EXISTING NOISE ENVIRONMENT

TABLE 6 Summary of Modeled Existing Noise Levels and Impact Assessment (end of Section 5)

Map ID Land Use/ FHWA Classification Exist Level (dBA) Noise Abatement Criteria R25 Residential/Category B 62 65 R26 Residential/Category B 65 65 R27 Residential/Category B 68 65 R28 Residential/Category B 66 65 R29 Residential/Category B 63 65 R30 Residential/Category B 68 65 R31 Residential/Category B 69 65 R32 Residential/Category B 65 65 R33 Residential/Category B 70 65 R34 Residential/Category B 65 65 R35 Residential/Category B 62 65 R36 Residential/Category B 67 65 R37 Residential/Category B 72 65 R38 Residential/Category B 70 65 R39 Residential/Category B 72 65 R40 Residential/Category B 71 65 R41 Residential/Category B 74 65 R42 Residential/Category B 66 65 R43 Residential/Category B 69 65 R44 Residential/Category B 63 65 R45 Residential/Category B 61 65 R46 Residential/Category B 69 65 R47 Residential/Category B 63 65 R48 Residential/Category B 66 65 R49 Residential/Category B 58 65 R50 Residential/Category B 65 65 R51 Residential/Category B 58 65 R52 Residential/Category B 64 65 R53 Residential/Category B 58 65 R54 Residential/Category B 63 65 RR1 Residential/Category B 70 65 RR2 Residential/Category B 70 65 RR3 Residential/Category B 70 65 RR4 Residential/Category B 66 65 RR5 Residential/Category B 65 65 RR6 Residential/Category B 65 65

34 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001 EXISTING NOISE ENVIRONMENT

TABLE 6 Summary of Modeled Existing Noise Levels and Impact Assessment (end of Section 5)

Map ID Land Use/ FHWA Classification Exist Level (dBA) Noise Abatement Criteria R55 Residential/Category B 60 65 R56 Residential/Category B 63 65 R57 Residential/Category B 61 65 R58 Residential/Category B 66 65 R59 Residential/Category B 66 65 R60 Residential/Category B 70 65 R61 Residential/Category B 67 65 R62 Residential/Category B 69 65 R63 Residential/Category B 69 65 R64 Residential/Category B 60 65 R65 Residential/Category B 67 65 R66 Residential/Category B 65 65 R67 Residential/Category B 65 65 C5 Commercial/Category C 63 70 C6 Commercial/Category C 70 70 Dimond to Dowling R68 Residential/Category B 63 65 R69 Residential/Category B 63 65 R70 Residential/Category B 63 65 R71 Residential/Category B 63 65 R72 Residential/Category B 67 65 R73 Residential/Category B 64 65 R74 Residential/Category B 65 65 R75 Residential/Category B 69 65 R76 Residential/Category B 66 65 C7 Commercial/Category C 66 70 C8 Commercial/Category C 69 70 C9 Commercial/Category C 69 70 C10 Commercial/Category C 70 70 C11 Commercial/Category C 69 70 C12 Commercial/Category C 68 70 C13 Commercial/Category C 71 70 C14 Commercial/Category C 69 70 C15 Commercial/Category C 72 70 C16 Commercial/Category C 68 70

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 35 ANC\053120001 EXISTING NOISE ENVIRONMENT

TABLE 6 Summary of Modeled Existing Noise Levels and Impact Assessment (end of Section 5)

Map ID Land Use/ FHWA Classification Exist Level (dBA) Noise Abatement Criteria C17 Commercial/Category C 70 70 Dowling to 36th M16 Residential/Category B 71 65 M17 Residential/Category B 69 65 M18 Residential/Category B 67 65 M19 Residential/Category B 70 65 R77 Residential/Category B 75 65 R78 Residential/Category B 75 65 R79 Residential/Category B 70 65 R80 Residential/Category B 66 65 R81 Residential/Category B 71 65 R82 Residential/Category B 64 65 R83 Residential/Category B 72 65 R84 Residential/Category B 68 65 R85 Residential/Category B 63 65 R86 Residential/Category B 71 65 R87 Residential/Category B 71 65 R88 Residential/Category B 63 65 R89 Residential/Category B 70 65 R90 Residential/Category B 67 65 R91 Residential/Category B 64 65 R92 Residential/Category B 67 65 R93 Residential/Category B 72 65 R94 Residential/Category B 65 65 R95 Residential/Category B 67 65 R96 Residential/Category B 73 65 R97 Residential/Category B 69 65 C18 Commercial/Category C 68 70 C19 Commercial/Category C 70 70 C20 Commercial/Category C 68 70 C21 Commercial/Category C 72 70 C22 Commercial/Category C 68 70 C23 Commercial/Category C 65 70 C24 Commercial/Category C 67 70 C25 Commercial/Category C 70 70

36 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001 EXISTING NOISE ENVIRONMENT

TABLE 6 Summary of Modeled Existing Noise Levels and Impact Assessment (end of Section 5)

Map ID Land Use/ FHWA Classification Exist Level (dBA) Noise Abatement Criteria C26 Commercial/Category C 69 70 Notes: Bold numbers indicate locations where existing noise levels already exceed the noise abatement criteria M12, M13, M17 and M18 have been adjusted based on the calibration

As shown in Table 6, the calculated existing peak-hour traffic noise levels approach or exceed the NAC at the following locations:

• Two single-family homes west of New Seward Highway, just north of the Specking Avenue cul-de-sac, represented by receiver R7

• The west side of the soccer field at Rabbit Creek Elementary School, exterior areas of the Baha’i Faith structure, and a single-family home at the southeast corner of Brayton and Tradewind drives, represented by receivers M4 and R9

• Homes along Brayton Drive just south of Huffman Road, represented by receiver R 15

• Units in Eagle Crest Apartments facing New Seward Highway, located east of the highway and south of East 112th Avenue, represented by receiver M9

• The multifamily homes located along Elcadore Drive, east of New Seward Highway, represented by receiver R21

• The homes in the Cedar Hollow Subdivision facing New Seward Highway, from the Cornerstone Church south of Thuja Avenue to north of Cedrus Court, represented by receivers R27, R28, R31, M11, R34, R38, R39, R41, and R42

• The single-family homes along Thimbleberry Drive, west of New Seward Highway, represented by receivers R30, R32, R33, R36, R37, R40, and R43

• The mobile homes from Jody Circle north to Stacey Circle, east of New Seward Highway, represented by receivers R46, R48, R58, R59, R60, R61, R62, and R63The mobile homes on the west side of the New Seward Highway south of Dimond Boulevard, represented by receivers RR1 through RR6

• The newly constructed single-family homes east of New Seward Highway, south of Dimond Boulevard, represented by receivers R65, R66, R67, and M15The homes east of the commercial district along Brayton Drive just south of 64th Avenue, represented by receivers R72 and R74

• The Polaris school located at the southeast corner of the Dowling Road interchange, represented by receivers R75 and R76

• The commercial district west of the New Seward Highway, generally from 68th Avenue north to 36th Avenue, represented by receivers C6, C10, C13, C15, C17, C19, C21, and C25

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 37 ANC\053120001 EXISTING NOISE ENVIRONMENT

• The first row of units in the Alpine Apartments, facing New Seward Highway south of Alpenhorn Avenue, represented by receivers R77, R78, M16, and R79

• The single-family homes along Becharof Street, east of New Seward Highway, represented by receivers R80, R81, M17, R83, R84, R87, R89, and R90

• Apartment structures along Homer Drive, south of Tudor Road, represented by receivers R86, M18, and R92

• The single-family homes along Saint Gotthard Street and Helvetia Drive, east of New Seward Highway and north of Tudor Road, represented by receivers R93, R94, M19, R95, R96, and R97

38 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001

SECTION 6 Future Noise Impacts

As described in Attachment B, the two proposed build alternatives each have two options. Both alternatives involve widening New Seward Highway, allowing for increased traffic volumes as development of the Anchorage Bowl progresses. Potential noise impacts associated with the proposed project include permanent impacts from vehicular traffic movements and changes to the physical characteristics of the roadway and temporary impacts related to roadway construction activities.

6.1 Traffic Noise Impacts Forecasted data for future (2035) traffic volumes used to evaluate the No-Build Alternative and build alternatives were obtained by using TransCAD software, Version 4.5. Attachment D shows the future peak-hour traffic used to predict noise levels. The FHWA TNM was used to calculate future (2035) traffic noise levels for the No-Build Alternative and build alternatives in terms of peak hour Leq. Table 7 presents the 2035 No- Build and Build Alternatives traffic noise level predictions. Although the project study area is defined as Rabbit Creek to 36th Avenue, improvements to New Seward Highway, cross streets, and frontage roads do not occur until north of O’Malley Road. Therefore future noise levels are the same south of O’Malley Road for the No-Build Alternative and Build Alternatives. Future (2035) traffic noise levels for the Build Alternative vary along the corridor. Increases of 3 to 4 dBA over existing levels are expected south of O’Malley Road. North of O’Malley Road, the increases are generally 5 dBA or less; exceptions occur between O’Malley Road and Dimond Boulevard, where the existing barriers would be removed to accommodate the expansion. These barriers would be replaced as part of the proposed project. Without replacement, increases for the receptors in this area would be as high 11 dBA (Table 7). Traffic noise level increases greater than 10 dBA are considered to be substantial increases by DOT&PF policy. Traffic noise level increases without the project would be between 1 and 4 dBA, well below the DOT&PF definition of substantial. Areas where future peak hour noise levels remain below the NAC under the No-Build Alternative only are as follows:

• Residential areas south of DeArmoun Road, represented by receivers M1 and R2 east of New Seward along Lake Otis Parkway

• Residential areas south of DeArmoun Road, represented by receivers M2 and R1 west of New Seward Highway at the end of Specking Avenue. This is protected by an existing noise barrier. The commercial districts along the New Seward Highway as represented by receivers C1, C2, C3, C4, C5, C7, C20, C23, and C24

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 39 ANC\053120001 FUTURE NOISE IMPACTS

TABLE 7 Comparison of Future Noise Impacts No Build (2035) Alternative 1 Option 1 Alternative 1 Option 2 Alternative 2 Option 1 Alternative 2 Option 2 Difference Difference Difference Difference Difference Difference Difference Difference Difference Map Exist from from from No from from No from from No from from No ID NAC (2005) Level Existing Level Existing Build Level Existing Build Level Existing Build Level Existing Build DeArmoun to Huffman M1 65 59 63 3 63 3 0 63 3 0 63 3 0 63 3 0 M2 65 58 61 4 61 4 0 61 4 0 61 4 0 61 4 0 M3 65 69 73 4 73 4 0 73 4 0 73 4 0 73 4 0 M4 65 69 72 4 72 4 0 72 4 0 72 4 0 72 4 0 M5 65 62 65 3 65 3 0 65 3 0 65 3 0 65 3 0 M6 65 61 65 3 65 3 0 65 3 0 65 3 0 65 3 0 M7 65 61 65 3 65 3 0 65 3 0 65 3 0 65 3 0 R1 65 60 63 3 63 3 0 63 3 0 63 3 0 63 3 0 R2 65 59 61 2 61 2 0 61 2 0 61 2 0 61 2 0 R3 65 62 65 3 65 3 0 65 3 0 65 3 0 65 3 0 R4 65 61 64 3 64 3 0 64 3 0 64 3 0 64 3 0 R5 65 60 63 3 63 3 0 63 3 0 63 3 0 63 3 0 R6 65 63 67 4 67 4 0 67 4 0 67 4 0 67 4 0 R7 65 68 72 4 72 4 0 72 4 0 72 4 0 72 4 0 R8 65 63 66 3 66 3 0 66 3 0 66 3 0 66 3 0 R9 65 67 70 3 70 3 0 70 3 0 70 3 0 70 3 0 R10 65 62 65 3 65 3 0 65 3 0 65 3 0 65 3 0 R11 65 59 62 3 62 3 0 62 3 0 62 3 0 62 3 0 R12 65 59 62 3 62 3 0 62 3 0 62 3 0 62 3 0 R13 65 62 65 3 65 3 0 65 3 0 65 3 0 65 3 0 R14 65 60 64 4 64 4 0 64 4 0 64 4 0 64 4 0 R15 65 67 71 4 71 4 0 71 4 0 71 4 0 71 4 0 R16 65 63 66 3 66 3 0 66 3 0 66 3 0 66 3 0 Huffman to O'Malley M8 65 60 63 3 63 3 0 63 3 0 63 3 0 63 3 0 M9 65 69 71 3 71 3 0 71 3 0 71 3 0 71 3 0 R17 65 61 64 3 64 3 0 64 3 0 64 3 0 64 3 0 R18 65 64 68 4 68 4 0 68 4 0 68 4 0 68 4 0 R19 65 65 68 3 68 3 0 68 3 0 68 3 0 68 3 0 R20 65 64 67 2 67 2 0 67 2 0 67 2 0 67 2 0 C1 70 42 44 3 44 3 0 44 3 0 44 3 0 44 3 0 C2 70 65 66 1 66 1 0 66 1 0 66 1 0 66 1 0

40 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001 FUTURE NOISE IMPACTS

TABLE 7 Comparison of Future Noise Impacts No Build (2035) Alternative 1 Option 1 Alternative 1 Option 2 Alternative 2 Option 1 Alternative 2 Option 2 Difference Difference Difference Difference Difference Difference Difference Difference Difference Map Exist from from from No from from No from from No from from No ID NAC (2005) Level Existing Level Existing Build Level Existing Build Level Existing Build Level Existing Build C3 70 61 64 3 64 3 0 64 3 0 64 3 0 64 3 0 C4 70 61 64 3 64 3 0 64 3 0 64 3 0 64 3 0 O'Malley to Dimond M10 65 64 66 2 66 1 -1 67 3 1 67 2 1 67 2 1 M11 65 69 71 1 71 1 0 71 1 0 71 1 0 71 1 0 M12 65 64 65 1 67 3 2 67 3 2 67 3 2 67 3 2 M13 65 59 61 2 63 4 2 63 4 2 63 4 2 63 4 2 M14 65 64 65 1 67 3 2 67 3 2 67 3 2 67 3 2 M15 65 67 69 2 70 3 1 70 3 1 70 3 1 70 3 1 R21 65 68 69 1 69 2 1 69 2 1 69 2 1 69 2 1 R22 65 64 66 1 69 5 4 69 5 4 69 5 4 69 5 4 R23 65 64 67 2 67 3 0 67 3 0 67 3 0 67 3 0 R24 65 63 66 3 67 4 1 67 4 1 67 4 1 67 4 1 R25 65 62 64 2 64 3 1 64 3 1 64 3 1 64 3 1 R26 65 65 67 2 68 3 1 68 3 1 68 3 1 68 3 1 R27 65 68 69 2 69 1 0 69 1 0 69 1 0 69 1 0 R28 65 66 67 2 68 2 1 68 2 1 68 2 1 68 2 1 R29 65 63 65 2 67 3 1 67 3 2 67 3 1 67 3 2 R30 65 68 70 2 71 3 2 71 3 2 71 3 2 71 3 2 R31 65 69 70 2 70 1 0 70 1 0 70 1 0 70 1 0 R32 65 65 67 2 68 2 1 68 3 1 68 3 1 68 2 1 R33 65 70 71 1 71 1 -1 71 1 0 71 1 -1 71 1 -1 R34 65 65 66 1 65 1 -1 65 1 -1 65 1 -1 65 1 -1 R35 65 62 64 1 63 1 -1 63 1 -1 63 1 -1 63 1 -1 R36 65 67 68 1 67 0 -2 67 0 -2 67 0 -2 67 0 -2 R37 65 72 73 1 72 1 -1 72 1 0 72 1 0 72 1 -1 R38 65 70 72 1 72 2 1 72 2 1 72 2 1 72 2 1 R39 65 72 73 1 74 2 1 74 2 1 74 2 1 74 2 1 R40 65 71 72 1 76 5 4 77 6 4 77 6 4 76 5 4 R41 65 74 75 1 76 2 1 76 2 1 76 2 1 76 3 1 R42 65 66 67 2 69 3 2 69 3 2 69 3 2 69 3 2 R43 65 69 71 1 73 4 2 73 4 3 73 4 3 73 4 2 R44 65 63 64 2 68 5 3 68 5 3 68 5 3 68 5 3

41 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001 FUTURE NOISE IMPACTS

TABLE 7 Comparison of Future Noise Impacts No Build (2035) Alternative 1 Option 1 Alternative 1 Option 2 Alternative 2 Option 1 Alternative 2 Option 2 Difference Difference Difference Difference Difference Difference Difference Difference Difference Map Exist from from from No from from No from from No from from No ID NAC (2005) Level Existing Level Existing Build Level Existing Build Level Existing Build Level Existing Build R45 65 61 62 2 65 4 2 65 4 2 65 4 2 65 4 2 R46 65 69 71 1 70 1 0 71 1 0 71 1 0 70 1 0 R47 65 63 65 2 66 3 1 66 3 1 66 3 1 66 3 1 R48 65 66 68 2 67 1 0 67 1 0 67 1 0 67 1 0 R49 65 58 60 2 63 4 2 63 4 2 63 4 2 63 4 2 R50 65 65 66 2 69 5 3 69 5 3 69 5 3 69 5 3 R51 65 58 60 1 64 6 4 64 6 4 64 6 4 64 6 4 R52 65 64 65 2 75 11 10 75 11 10 75 11 10 75 11 10 R53 65 58 59 1 67 9 7 67 9 7 67 9 7 66 9 7 R54 65 63 65 1 63 0 -2 63 0 -2 63 0 -2 63 0 -2 RR1 65 70 72 1 72 2 1 72 2 1 72 2 1 72 2 1 RR2 65 70 71 1 72 2 1 72 2 1 72 2 1 72 2 1 RR3 65 70 72 1 73 2 1 73 2 1 73 2 1 73 2 1 RR4 65 66 67 1 69 4 2 70 4 2 70 4 2 70 4 2 RR5 65 65 67 1 69 4 2 69 4 3 69 4 3 69 4 3 RR6 65 65 67 2 70 5 4 70 5 4 70 5 4 70 5 4 R55 65 60 61 1 67 8 6 67 8 6 67 8 6 67 8 6 R56 65 63 64 1 72 9 8 72 9 8 72 9 8 72 9 8 R57 65 61 62 1 68 7 6 68 7 6 68 7 6 68 7 6 R58 65 66 68 2 74 8 6 74 8 6 74 8 6 74 8 6 R59 65 66 67 1 70 4 3 70 4 3 70 4 3 70 4 3 R60 65 70 72 1 74 4 2 74 4 2 74 4 2 74 4 2 R61 65 67 69 1 70 3 2 70 3 2 70 3 2 70 3 2 R62 65 69 71 2 74 5 3 74 5 3 74 5 3 74 5 3 R63 65 69 70 1 74 5 4 74 5 4 74 5 4 74 5 3 R64 65 60 61 1 64 4 3 64 4 3 64 4 3 64 4 3 R65 65 67 70 3 71 4 1 71 4 1 71 4 1 71 4 1 R66 65 65 67 2 69 4 2 69 4 2 69 4 2 69 4 2 R67 65 65 67 2 68 3 1 68 3 1 68 3 1 68 3 1 C5 70 63 65 2 65 2 0 65 2 0 65 2 0 65 2 0 C6 70 70 72 2 71 1 -1 71 1 -1 71 1 -1 71 1 -1

42 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001 FUTURE NOISE IMPACTS

TABLE 7 Comparison of Future Noise Impacts No Build (2035) Alternative 1 Option 1 Alternative 1 Option 2 Alternative 2 Option 1 Alternative 2 Option 2 Difference Difference Difference Difference Difference Difference Difference Difference Difference Map Exist from from from No from from No from from No from from No ID NAC (2005) Level Existing Level Existing Build Level Existing Build Level Existing Build Level Existing Build Dimond to Dowling R68 65 63 65 2 68 5 3 68 5 3 68 5 3 68 5 3 R69 65 63 65 2 69 6 4 69 6 4 69 6 4 69 6 4 R70 65 63 65 2 68 5 3 68 5 3 68 5 3 68 5 3 R71 65 63 64 2 66 4 2 66 4 2 67 4 2 67 4 2 R72 65 67 70 2 70 2 0 70 2 0 70 2 0 70 2 0 R73 65 64 66 2 66 2 0 66 2 1 66 2 0 66 2 0 R74 65 65 67 2 69 4 2 69 4 2 69 4 2 69 4 2 R75 65 69 72 3 71 2 -1 72 2 -1 72 2 -1 72 2 -1 R76 65 66 69 3 70 3 1 70 3 1 70 3 1 70 3 1 C7 70 66 68 2 69 2 0 69 2 0 69 2 0 69 2 0 C8 70 69 70 1 69 0 -1 69 0 -1 69 0 -1 70 1 0 C9 70 69 71 2 72 3 1 72 3 1 72 3 1 72 3 1 C10 70 70 72 2 72 2 0 72 2 0 72 2 0 72 2 0 C11 70 69 71 2 73 4 2 73 4 2 73 4 2 73 4 2 C12 70 68 70 2 71 3 1 71 3 1 72 3 1 72 3 1 C13 70 71 72 2 73 3 1 73 3 1 73 3 1 73 3 1 C14 70 69 71 2 72 3 1 72 3 1 72 3 1 72 3 1 C15 70 72 74 2 73 1 -1 73 1 0 73 1 0 73 1 -1 C16 70 68 71 2 73 5 3 73 5 3 73 5 3 73 5 3 C17 70 70 72 2 72 2 0 72 2 0 72 2 0 72 2 0 Dowling to 36th M16 65 71 73 2 72 1 -1 72 1 -1 72 1 -1 71 1 -1 M17 65 69 71 2 69 0 -2 69 0 -2 69 0 -2 69 0 -2 M18 65 67 68 1 70 3 2 71 4 3 69 2 1 69 2 1 M19 65 70 72 2 75 5 3 75 5 3 75 5 3 75 5 3 R77 65 75 77 2 76 1 -1 76 1 -1 73 -3 -5 74 -2 -4 R78 65 75 78 2 76 0 -2 76 0 -2 74 -1 -3 75 -1 -3 R79 65 70 72 2 72 2 0 72 2 0 72 2 0 72 2 0 R80 65 66 68 2 69 3 1 69 3 1 68 2 0 68 2 0 R81 65 71 73 2 72 1 -1 72 1 -1 71 -1 -2 71 0 -2 R82 65 64 66 2 71 7 5 71 8 6 70 7 4 70 6 4 R83 65 72 74 2 75 2 1 75 3 1 75 2 1 75 2 1

43 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001 FUTURE NOISE IMPACTS

TABLE 7 Comparison of Future Noise Impacts No Build (2035) Alternative 1 Option 1 Alternative 1 Option 2 Alternative 2 Option 1 Alternative 2 Option 2 Difference Difference Difference Difference Difference Difference Difference Difference Difference Map Exist from from from No from from No from from No from from No ID NAC (2005) Level Existing Level Existing Build Level Existing Build Level Existing Build Level Existing Build R84 65 68 69 2 71 3 2 71 4 2 71 4 2 71 4 2 R85 65 63 65 2 69 6 4 69 6 4 68 5 3 68 5 3 R86 65 71 72 2 73 2 1 73 3 1 73 2 1 73 2 1 R87 65 71 72 2 73 2 1 73 3 1 73 2 0 74 3 1 R88 65 63 65 2 69 6 4 69 6 4 69 5 3 69 6 4 R89 65 70 72 2 73 3 1 73 3 1 73 3 1 74 4 2 R90 65 67 69 2 72 5 3 73 6 3 72 5 3 77 9 7 R91 65 64 66 2 68 4 1 68 4 2 67 4 1 70 7 4 R92 65 67 70 3 69 2 -1 69 2 -1 69 2 -1 69 2 -1 R93 65 72 73 2 68 -4 -6 73 2 0 74 3 1 74 3 1 R94 65 65 67 2 65 0 -1 67 2 1 67 2 1 68 3 1 R95 65 67 68 2 72 5 4 72 5 4 72 5 4 72 6 4 R96 65 73 75 2 79 6 5 79 6 5 79 6 5 79 6 5 R97 65 69 70 2 73 5 3 73 5 3 73 5 3 74 5 3 C18 70 68 70 2 70 2 0 70 2 0 70 2 0 70 2 0 C19 70 70 72 1 72 1 0 72 2 1 71 0 -1 70 0 -1 C20 70 68 69 2 71 3 2 71 4 2 71 3 2 71 3 1 C21 70 72 73 2 75 3 2 76 4 2 75 4 2 75 3 2 C22 70 68 71 3 71 3 0 71 3 1 71 3 0 72 4 2 C23 70 65 67 3 67 2 -1 67 3 0 67 2 -1 69 5 2 C24 70 67 69 2 70 3 1 76 9 6 70 3 1 70 3 1 C25 70 70 72 2 71 1 -1 71 1 -2 71 1 -1 71 1 -1 C26 70 69 72 2 71 2 0 71 2 0 71 2 0 71 2 0 Notes: Bold numbers indicate locations where noise levels exceed the noise abatement criteria M12, M13, M17 and M18 have been adjusted based on the calibration

44 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001 FUTURE NOISE IMPACTS

• Residential areas and a church from Legacy Drive to Steeple Drive, represented by receivers R4 and M6 east of New Seward Highway.

• Residential areas along the west side of New Seward Highway from the north end of Elmhurst Drive north to Huffman Road, represented by receivers, R5, R11, R12, M7, and R14. This is protected by an existing noise barrier.

• Residential areas near the end of Oren Street south of O’Malley Road, represented by receiver R17 west of New Seward Highway due to distance from road

• Second-row residential area between Chinaberry Circle and Balfour Drive, represented by receiver R44 west of New Seward Highway due to distance from road

• Residence at the end of Surrey Circle, represented by receiver M13, west of New Seward Highway

• Second- and third-row mobile homes in the Southwood Manor Trailer Court near Gelien Loop, represented by receivers R45, R49, R51, R53, and R57, east of New Seward Highway due to distance from road

• Residences at the intersection of 68th Avenue and Meadow Street, represented by receiver R71, east of New Seward Highway due to distance from road In some areas, future levels of peak-hour noise would approach or exceed the NAC under the future No-Build Alternative, but would remain below the NAC if the proposed project is implemented. These areas are listed below:

• Second- and third-row mobile homes between Thuja Avenue and Cedrus Drive in the Southwood Manor Trailer Court, represented by receivers R34 and R35, east of New Seward Highway

• Third-row residences between Balfour Drive and Surrey Circle, represented by receiver R47, west of New Seward Highway due to distance from road

• Residential areas along Morningside Loop, represented by receiver R54, west of New Seward Highway due to distance from road

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 45 ANC\053120001 FUTURE NOISE IMPACTS

46 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001

SECTION 7 Mitigation

7.1 Traffic Noise Mitigation The DOT&PF Noise Abatement Policy (1996) directs that noise abatement measures be considered when the predicted noise levels approach or exceed the NAC. The DOT&PF noise policy defines “approach” as within 2 dBA of the FHWA NAC (the resulting levels are shown in Table 2) and substantial increase as 10 dBA. Consequently, noise abatement would be considered for any location where peak-hour noise levels equal or exceed the levels specified in Table 2 or future peak-hour noise levels increase by 10 dBA or more over existing noise levels. Potential traffic noise abatement measures that may be considered include the following:

• Construction of noise barriers between the roadway and residential locations where future peak-hour noise levels exceed the NAC

• Realignment of the roadway, horizontally and/or vertically

• Implementation of traffic management measures (reduced speed limits, limitations, or restrictions on truck traffic)

• Provide noise insulation for public buildings

• Acquisition of “buffer zones” between the roadway and affected properties Of the above noise abatement measures, the noise barrier option is usually the most practical and effective choice. Substantial realigning of New Seward Highway would not be feasible without considerable property acquisitions. For the same reason, creation of buffer zones is not a viable option for noise abatement. Additionally, traffic management measures, such as lowering the speed limit or limiting truck traffic, do not meet the project purpose and need. Because the proposed action is a Type I project that adds through traffic lanes and capacity, the DOT&PF noise policy and 23 CFR 772 apply. The latter requires that “before adoption of a final environmental impact statement or finding of no significant impact, the highway agency shall identify noise abatement measures which are reasonable and feasible and which are likely to be incorporated in the project.”

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 47 ANC\053120001 MITIGATION

On June 12, 1995, the FHWA issued revised guidance on traffic noise analysis and a memorandum to require all state highway agencies to adopt written noise policies according to the revised guidelines (DOT&PF, 1996). To meet this requirement, the DOT&PF developed its Noise Abatement Policy (1996), establishing specific requirements, including feasibility and reasonableness criteria, for highway noise abatement. Following is a synopsis of the DOT&PF Noise Abatement Policy pertinent to this analysis:

• Noise barriers will not be constructed for Category C and D land uses, which include but are not limited to, industrial and commercial uses and undeveloped lands, unless it is necessary to protect adjacent sensitive uses (land use Categories A and B). As a result, noise barriers were evaluated for residential receivers only. Undeveloped lands include those lands for which a building permit has not been obtained by the date that the environmental document is signed. Existing building permits may be considered to address this criterion during the preparation of the environmental document.

• Noise barrier construction is not feasible if a minimum noise reduction of 5 dBA cannot be achieved. Noise abatement measures that do not achieve at least a 5-dBA reduction in noise, to most protected receivers, are not prudent expenditures of public funds, because any less of a reduction is not easily perceived in a field situation.

• The reasonableness of a noise barrier has to be determined by thoroughly considering a wide range of criteria, such as the amount of noise reduction provided, number of people protected, cost of abatement, views and opinions of affected residents, and potential environmental impacts of noise barrier construction.

• Noise barriers will only be constructed if they have been determined to be both feasible and reasonable.

7.2 Noise Barrier Analysis The TNM (Version 2.1) was used to determine the noise-level reduction provided by noise barriers at locations where noise levels approach or exceed the NAC. See Figures 8, 9, 10, and 11. This model calculates barrier insertion loss by accounting for variables such as distance from source to barrier, distance from barrier to receiver, source and receiver elevations, and barrier height. Several existing noise barriers are located along the New Seward Highway corridor south of Dimond Boulevard and were sited before the 1996 DOT&PF Noise Abatement Policy. These barriers would either remain or be replaced in kind (relocated), as follows:

• An existing noise barrier is located in the northwest quadrant of New Seward Highway and DeArmoun Road. This wall is approximately 250 feet.

• A noise barrier, approximately 4,100 feet long, extends from the northern end of Bell’s Nursery, west of New Seward Highway, along the existing highway right-of-way to Huffman Road.

48 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001

MITIGATION

• East of New Seward Highway, a noise barrier is located in the northeast quadrant of DeArmoun Road and the New Seward Highway. The barrier is approximately 400 feet long.

• A noise barrier located east of New Seward Highway begins just south of Tradewind Drive on the west side of Brayton Drive and extends north approximately 2,600 feet, ending south of Riffle Lane.

• North of Huffman Road and west of New Seward Highway is an existing noise barrier approximately 600 feet long and beginning south of East Klatt Road.

• South of O’Malley Road and west of New Seward Highway is an existing noise barrier approximately 500 feet long and adjacent to the mainline near Oren Street.

• North of O’Malley Road and east of New Seward Highway, two barriers protect most of the Southwood Manor Trailer Court. The southernmost barrier begins north of Donna Drive east of Brayton Drive and extends for approximately 500 feet. The second barrier begins south of Gross Circle between Brayton Drive and New Seward Highway and extends 1,000 feet to Gelien Loop. These barriers would be removed and replaced under the Build Alternative. The DOT&PF Noise Abatement Policy (1996) requires that a determination of technical feasibility and economic reasonability of noise barriers be made before a decision to recommend a barrier can be rendered. As stated previously, a noise barrier is feasible if a minimum reduction of 5 dBA is achieved and reasonableness should be determined by considering the amount of noise reduction provided, number of people protected, cost of abatement, views and opinions of affected residents, and potential environmental impacts of noise barrier construction. The test for one criterion of reasonableness, cost, is determined by dividing the estimated total cost of the noise barrier by the number of residential units that receive a minimum of 5-dBA reduction in noise level (regardless of whether the residence was identified as a location at which the NAC was exceeded). If this cost is $25,000 per residence or less, the barrier is deemed economically reasonable. If this cost is exceeded, the noise abatement measures would typically not be recommended. Many densely packed residential areas lie immediately adjacent to New Seward Highway. Given their proximity to the highway, these areas are predicted to exceed the NAC, and given their density, it is typically regarded as possible to achieve a feasibly reduction (5 dBA) for a cost of less than $25,000 per benefited residences. Ultimate barrier locations would be developed during final design to ensure that each barrier is placed appropriately to achieve maximum reduction for minimal cost without presenting a safety or snow removal hazard. The analysis is summarized below by area. O’Malley Road to Dimond Boulevard Residential uses are found on both sides of New Seward Highway. On the east side of New Seward Highway, existing barriers would be removed to accommodate the Build Alternative. A barrier wall system (B1) extending from O’Malley Road to 92nd Avenue is proposed on the east side of New Seward Highway. Similarly, on the west side of New Seward Highway, a new barrier (B2) that starts near the O’Malley Road off-ramp and

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extends north to 92nd Avenue is recommended. These barriers are both feasible and reasonable as detailed below:

TABLE 8 Barrier B1 Design

Height Length Area (ft) (ft) (sq ft)

Barrier B1a 10 400 4000 12 300 3600 14 100 1400 16 100 1600 14 100 1400 12 675 8100 Barrier B1b 14 400 5600 16 200 3200 18 300 5400 16 100 1600 14 100 1400 12 200 2400 10 1300 13000 12 100 1200 14 400 5600 Barrier B1c 14 500 7000 16 295 4720 Barrier B1d 20 585 7000

TABLE 9 Barrier B1 Noise Reduction

Noise Reduction No Barrier With Barrier Calculated Receiver Calculated Calculated Calculated Minus Goal ≥5dB Number Leq dBA Leq dBA dB Goal dB dB Reduction? M10 68 56 12 5 7 Yes M11 71 66 5 5 0 Yes M12 67 61 6 5 1 Yes M14 74 66 8 5 3 Yes R21 69 62 7 5 2 Yes R22 69 61 8 5 3 Yes R23 67 59 8 5 3 Yes R24 67 61 6 5 1 Yes

58 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001 MITIGATION

TABLE 9 Barrier B1 Noise Reduction

Noise Reduction No Barrier With Barrier Calculated Receiver Calculated Calculated Calculated Minus Goal ≥5dB Number Leq dBA Leq dBA dB Goal dB dB Reduction? R25 64 59 5 5 0 Yes R26 68 62 6 5 1 Yes R27 69 64 5 5 0 Yes R28 68 63 5 5 0 Yes R29 67 61 6 5 1 Yes R31 70 64 6 5 1 Yes R34 65 60 5 5 0 Yes R35 63 58 5 5 0 Yes R38 72 66 6 5 1 Yes R39 73 68 5 5 0 Yes R41 76 71 5 5 0 Yes R42 69 63 6 5 1 Yes R45 65 59 6 5 1 Yes R46 70 64 6 5 1 Yes R48 69 63 6 5 1 Yes R49 65 58 7 5 2 Yes R51 69 60 9 5 4 Yes R52 76 66 10 5 5 Yes R53 68 61 7 5 2 Yes R55 67 61 6 5 1 Yes R56 72 68 4 5 -1 No R57 68 62 6 5 1 Yes R58 74 62 12 5 7 Yes R59 70 66 4 5 -1 No R60 74 66 8 5 3 Yes R61 70 67 3 5 -2 No R62 73 68 5 5 0 Yes R63 74 71 3 5 -2 No R64 64 63 1 5 -4 No Note: Barrier 1 includes B1a, B1b, B1c and B1d

Estimated Cost: $2,113,000 Number of Benefited Receivers: 185 Cost per Benefited Receiver: $11,500

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TABLE 10 Barrier B2 Design

Height Length Area (ft) (ft) (sq ft) 8 200 1600 10 100 1000 12 300 3600 14 600 8400 18 2013 36234

TABLE 11 Barrier B2 Noise Reduction

With Noise Reduction No Barrier Barrier Receiver Calculated Calculated Calculated Calculated ≥5dB Number Leq dBA Leq dBA dB Goal dB Minus Goal dB Reduction? M13 64 60 4 5 -1 No R30 71 64 7 5 2 Yes R33 71 63 8 5 3 Yes R37 72 63 9 5 4 Yes R40 77 65 12 5 7 Yes R43 73 63 10 5 5 Yes R50 70 65 5 5 0 Yes RR1 72 62 10 5 5 Yes RR2 72 64 8 5 3 Yes RR3 73 67 6 5 1 Yes RR4 70 64 6 5 1 Yes RR5 69 65 4 5 -1 No RR6 70 69 1 5 -4 No Note: M13 has been adjusted based on calibration

Estimated Cost: $1,570,920 Number of Benefited Receivers: 80 Cost per Benefited Receiver: $19,637

60 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001 MITIGATION

A developing area south of Dimond Boulevard on the east side of New Seward Highway (represented by receptors R65 to R67) could become a candidate for a noise barrier. The apparent driveway configuration and the proximity to the frontage road and off-ramp merge could compromise the effectiveness of a barrier at this location. A detailed analysis would be performed after the parcel has been performed or during the design phase. Dimond Boulevard to Dowling Road Land use on the west side of New Seward Highway is commercial. According to DOT&PF policy, noise barriers are not considered consistent with commercial land uses. On the east side of New Seward Highway, a residential neighborhood exists north of Lore Road; however, this area is set back approximately 400 feet from the highway (receptors R68 to R71). The land use between New Seward Highway and these residential areas is commercial. Therefore, a noise barrier is not recommended at this location. Just south of Dowling Road is the K-12 Polaris School, represented by receptors R75 and R76. Because the primary outdoor use area, the playfield east of the school, is an area where a reduced noise level would not necessarily be of benefit, the time of use would not necessarily correlate with the peak-hour noise conditions modeled here, and there were no outdoor use areas outside the classrooms identified, the interior noise levels were evaluated. The buildings are of arctic construction and, consistent with FHWA guidance, are estimated to achieve an outdoor to indoor noise reduction of between 25 dBA and 35 dBA. Given that the predicted exterior levels range from 70 to 72 dBA, even the lower estimated reduction of 25 dBA achieves compliance with the interior NAC of 50 dBA. Therefore, a noise barrier is not recommended to reduce noise levels at this school. Dowling Road to Tudor Road The land uses on the west side of New Seward Highway between Dowling Road and Campbell Creek are commercial. North of Campbell Creek to Tudor Road is a newly developed residential area (receptor R82) and existing residential uses (receptors R86 and R92). Barrier 9, which extends from Campbell Creek to Tudor Road, was determined to be both reasonable and feasible; therefore, it is recommended as detailed below. Barrier 9 is 10 feet in height. Exterior outdoor use areas on the east side of New Seward Highway were identified at the Alpine Apartments (receptors R77 to R79 and M16) located between Mockingbird Drive and Alpenhorn Avenue. Barrier B6 extends between these two roads and is recommended because it was found to provide a 5-dBA reduction to ground level areas and satisfies the reasonable cost criteria as detailed below. Also on the east side of New Seward Highway, between Campbell Creek and Tudor Road, the area represented by receptors R80, R81, and R83 to R91 is predicted to exceed the NAC. A barrier system (B7-8) has been found to be both reasonable and feasible and is therefore recommended as detailed below. The barrier system B7-8 is 12 feet in height.

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TABLE 12 Barrier B6 Design

Height (ft) Length (ft) Area (sq ft) 10 350 3500 12 50 600 14 50 700 16 250 4000 14 50 700 12 200 2400

TABLE 13 Barrier B6 Noise Reduction – Alternative 1, Option 1

No Barrier With Barrier Calculated Calculated Calculated Noise Reduction Minus

Receiver Leq Leq Calculated Goal Goal ≥5dB Number dBA dBA dB dB dB Reduction? M16 72 67 5 5 0 Yes R77 76 68 8 5 3 Yes R78 75 67 8 5 3 Yes R79 72 66 6 5 1 Yes

TABLE 14 Barrier B6 Noise Reduction – Alternative 1, Option 2

No Barrier With Barrier Calculated Calculated Calculated Noise Reduction Minus

Receiver Leq Leq Calculated Goal Goal ≥5dB Number dBA dBA dB dB dB Reduction? M16 72 68 4 5 -1 Yes R77 76 68 8 5 3 Yes R78 76 67 9 5 4 Yes R79 72 67 5 5 0 Yes

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TABLE 15 Barrier B6 Noise Reduction – Alternative 2, Option 1

No Barrier With Barrier Calculated Calculated Calculated Noise Reduction Minus

Receiver Leq Leq Calculated Goal Goal ≥5dB Number dBA dBA dB dB dB Reduction? M16 72 66 6 5 1 Yes R77 74 68 6 5 1 Yes R78 75 70 5 5 0 Yes R79 72 66 6 5 1 Yes

TABLE 16 Barrier B6 Noise Reduction – Alternative 2, Option 2

No Barrier With Barrier Calculated Calculated Calculated Noise Reduction Minus

Receiver Leq Leq Calculated Goal Goal ≥5dB Number dBA dBA dB dB dB Reduction? M16 72 66 6 5 1 Yes R77 74 68 6 5 1 Yes R78 75 70 5 5 0 Yes R79 72 66 6 5 1 Yes

Estimated Cost: $289,806 Number of Benefited Receivers: 15 Cost per Benefited Receiver: $19,320

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 63 ANC\053120001 MITIGATION

TABLE 17 Barrier B7-8 Noise Reduction—Alternative 1, Option 1

Noise Reduction No Barrier With Barrier Calculated Receiver Calculated Calculated Calculated Minus Goal ≥5dB

Number Leq dBA Leq dBA dB Goal dB dB Reduction? M17 71 64 7 5 2 Yes R80 68 63 5 5 0 Yes R81 71 66 5 5 0 Yes R83 74 65 9 5 4 Yes R84 71 65 6 5 1 Yes R85 67 62 5 5 0 Yes R87 72 64 8 5 3 Yes R88 66 62 4 5 -1 No R89 72 68 4 5 -1 No R90 72 66 6 5 1 Yes R91 66 64 2 5 -3 No

TABLE 18 Barrier B7-8 Noise Reduction—Alternative 1, Option 2

Noise Reduction No Barrier With Barrier Calculated Receiver Calculated Calculated Calculated Minus Goal ≥5dB

Number Leq dBA Leq dBA dB Goal dB dB Reduction?

M17 71 65 6 5 1 Yes R80 68 63 5 5 0 Yes R81 71 66 5 5 0 Yes R83 74 66 8 5 3 Yes R84 71 65 6 5 1 Yes R85 67 63 4 5 -1 No R87 72 64 8 5 3 Yes R88 66 62 4 5 -1 No R89 72 69 3 5 -2 No R90 72 66 6 5 1 Yes R91 67 64 3 5 -2 No

64 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001 MITIGATION

TABLE 19 Barrier B7-8 Noise Reduction—Alternative 2, Option 1

Noise Reduction No Barrier With Barrier Calculated Receiver Calculated Calculated Calculated Minus Goal ≥5dB

Number Leq dBA Leq dBA dB Goal dB dB Reduction?

M17 71 63 8 5 3 Yes R80 67 63 4 5 -1 Yes R81 70 65 5 5 0 Yes R83 73 68 5 5 0 Yes R84 71 64 7 5 2 Yes R85 66 62 4 5 -1 Yes R87 72 63 9 5 4 Yes R88 66 62 4 5 -1 No R89 71 68 3 5 -2 No R90 72 65 7 5 2 Yes R91 66 63 3 5 -2 No

TABLE 20 Barrier B7-8 Noise Reduction—Alternative 2, Option 2

Noise Reduction No Barrier With Barrier Calculated Receiver Calculated Calculated Calculated Minus Goal ≥5dB

Number Leq dBA Leq dBA dB Goal dB dB Reduction?

M17 71 63 8 5 3 Yes R80 67 63 4 5 -1 No R81 70 65 5 5 0 Yes R83 74 67 7 5 2 Yes R84 71 64 7 5 2 Yes R85 67 63 4 5 -1 No R87 73 64 9 5 4 Yes R88 68 66 2 5 -3 No R89 73 69 4 5 -1 No

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TABLE 21 Barrier B7-8 Noise Reduction—Alternative 2, Option 1

Noise Reduction No Barrier With Barrier Calculated Receiver Calculated Calculated Calculated Minus Goal ≥5dB

Number Leq dBA Leq dBA dB Goal dB dB Reduction?

R90 72 65 7 5 2 Yes R91 66 63 3 5 -2 No

Estimated Cost: $ 479,041 Number of Approximate Benefited Receivers: 29 Cost per Benefited Receiver: $16,519

TABLE 22 Barrier B9 Noise Reduction—Alternative 1, Option 1

Noise Reduction No Barrier With Barrier Calculated Receiver Calculated Calculated Calculated Minus Goal ≥5dB

Number Leq dBA Leq dBA dB Goal dB dB Reduction? M18 70 64 6 5 1 Yes R82 71 67 4 5 -1 No R86 73 67 6 5 1 Yes R92 68 63 5 5 0 No

TABLE 23 Barrier B9 Noise Reduction—Alternative 1, Option 2

Noise Reduction No Barrier With Barrier Calculated Receiver Calculated Calculated Calculated Minus Goal ≥5dB

Number Leq dBA Leq dBA dB Goal dB dB Reduction? M18 71 65 6 5 1 Yes R82 71 67 4 5 -1 No R86 74 68 6 5 1 Yes R92 68 63 5 5 0 No

66 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001 MITIGATION

TABLE 24 Barrier B9 Noise Reduction—Alternative 2, Option 1

Noise Reduction No Barrier With Barrier Calculated Receiver Calculated Calculated Calculated Minus Goal ≥5dB

Number Leq dBA Leq dBA dB Goal dB dB Reduction?

M18 69 62 7 5 2 Yes R82 70 66 4 5 -1 No R86 73 67 6 5 1 Yes R92 68 63 5 5 0 Yes

TABLE 25 Barrier B9 Noise Reduction—Alternative 2, Option 2

Noise Reduction No Barrier With Barrier Calculated Receiver Calculated Calculated Calculated Minus Goal ≥5dB

Number Leq dBA Leq dBA dB Goal dB dB Reduction?

M18 69 62 7 5 2 Yes R82 70 66 4 5 -1 No R86 73 67 6 5 1 Yes R92 69 63 6 5 1 Yes

Estimated Cost: $507,596 Number of Approximate Benefited Receivers: 25 Cost per Benefited Receiver: $20,300

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 67 ANC\053120001 MITIGATION

Tudor Road to 36th Avenue Land uses on the west side of New Seward Highway are commercial throughout this segment of highway, and no barriers are recommended. On the east side of New Seward Highway, the residential area represented by receivers R93 to R97 is predicted to exceed the NAC. It is feasible and reasonable to achieve a 5-dBA reduction at the first row of residences; therefore, barrier 10 is recommended

TABLE 26 Barrier B10 Noise Reduction—Alternative 1, Option 1

Noise Reduction No Barrier With Barrier Calculated Receiver Calculated Calculated Calculated Minus Goal ≥5dB

Number Leq dBA Leq dBA dB Goal dB dB Reduction?

M19 75 70 5 5 0 Yes R93 74 66 8 5 3 Yes R94 68 64 4 5 -1 No R95 73 70 3 5 -2 No R96 76 67 6 5 1 Yes R97 73 69 4 5 -1 No

Estimated Cost: $184,063 Number of Approximate Benefited Receivers: 8 Cost per Benefited Receiver: $23,008

The above noise barrier recommendations are based on preliminary engineering, existing conditions, and policies. A final decision on noise abatement would be made upon completion of the final design and public involvement process.

68 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001

SECTION 8 Construction Noise

During the construction phase, noise from construction activities would add to the noise environment in the immediate project area. Activities involved in construction would generate noise levels, as indicated in Table 27, ranging from 82 to 86 dBA at a distance of 30 meters (100 feet). Construction activities would be temporary in nature and are anticipated to occur during normal daytime working hours, although work at night is possible to reduce the length of construction period and to avoid traffic disruption during the day. Construction noise impacts could result in annoyance or sleep disruption if nighttime operations occur or if unusually noisy equipment is used. Because of these effects, construction activities rarely occur during nighttime periods.

TABLE 27 Construction Equipment Noise

Maximum Sound Level at Construction Phase Loudest Equipment 30 Meters (100 Feet) (dBA)

Clearing and grubbing Bulldozer, backhoe 83 dBA

Earthwork Scraper, bulldozer 85 dBA

Foundation Backhoe, loader 82 dBA

Superstructure Crane, loader 83 dBA

Base preparation Truck, bulldozer 85 dBA

Paving Paver, truck 86 dBA Source: U.S. Department of Transportation, 1977

Noise would also be generated during the construction phase by increased truck traffic on area roadways associated with transport of heavy materials and equipment. This noise increase would be of short duration, and would probably occur primarily during daytime hours. Work would be done in accordance with Municipal Ordinance. Should work occur at night, then a noise permit would be required from the Municipality. This permit would likely include conditions that specify advanced notice to adjacent property owners of nighttime operations and special conditions and restrictions on specific activities.

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70 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001

SECTION 9 Conclusions

As a result of the traffic noise analysis, the following conclusions are presented:

• Noise levels for existing peak-hour traffic approach or exceed the FHWA and DOT&PF NAC at 75 of the identified noise-sensitive receivers. Noise levels for peak-hour traffic approach or exceed the NAC at 116 locations under the future (2035) No-Build Alternative. The NAC are exceeded at 122 locations under Build Alternative 1, Option 1 and Option 2, and Build Alternative 2, Option 1, and at 123 locations under future Build Alternative 2, Option 2.

• The calculated noise levels show that future increases above existing noise levels would be up to 4 dBA under the No-Build Alternative and vary from 4 dBA below existing to 11 dBA above existing under the build alternatives. At some locations the increases in future noise levels would exceed the DOT&PF substantial increase threshold of 10 dBA or more.

• At this time, the following noise barriers are considered feasible and reasonable, and are likely to be incorporated into the proposed project: Barriers B1, B2, B6, B7-8, B9 & B10. These noise barriers meet DOT&PF cost reasonableness criterion of $25,000 per benefited receiver and reduce future noise levels for peak-hour traffic related to the proposed project by 5 dBA or more. These barriers are shown to be both feasible and reasonable; therefore, they are recommended for construction. All existing barriers would remain in place or would be reconstructed. The recommendations provided are based on preliminary design information and current state and federal laws and policies. These recommendations would be reevaluated during the design of each construction phase of the proposed project.

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 71 ANC\053120001 CONCLUSIONS

72 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001

SECTION 10 List of Preparers

Dan Sterley/CH2M HILL — Project Manager Farshad Farhang/CH2M HILL – Noise Analysis Task Manager Mark Bastasch/CH2M HILL – Noise Analyst Nichole Rehm/CH2M HILL – Noise Analyst Natalie Liljenwall/CH2M HILL – Noise Analyst Jorge Monroy/CH2M HILL – Graphics Bryce Stath/CH2M HILL – Geographic Information System (GIS) Mapping

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE 73 ANC\053120001 LIST OF PREPARERS

74 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001

SECTION 11 References

Alaska Department of Transportation and Public Facilities. March 1996. Noise Abatement Policy. CH2M HILL. September 2004. New Seward Highway Rabbit Creek to 36th Avenue Preliminary Engineering Report. Federal Highway Administration. 1987. Technical Advisory T6640.8A — Guidance for Preparing and Processing Environmental and Section 4(F) Documents. Federal Highway Administration. 1992. Procedures for Abatement of Highway Traffic Noise and Construction Noise. Code of Federal Regulations, Title 23, Part 772. Federal Highway Administration. January 1998a. FHWA Traffic Noise Model User’s Guide. Report No. FHWA-PD-96-009. Federal Highway Administration, Washington D.C. Federal Highway Administration. February 1998b. Traffic Noise Model Technical Manual. Report No. FHWA-PD-96-010. Washington D.C. Municipality of Anchorage, Alaska Department of Transportation and Public Facilities, and Anchorage Metropolitan Area Transportation Solutions. December 2005. Anchorage Bowl 2025 Long-Range Transportation Plan. U.S. Department of Transportation. 1977. Highway Construction Noise: Measurement, Prediction, and Mitigation.

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76 NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001

ATTACHMENT A Acoustical Terminology

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ATTACHMENT A Acoustical Terminology

Ambient Noise (Level) - All-encompassing noise (level) at a given place and time, usually a composite of sounds from all sources near and far, including any specific source(s) of interest. A-Weighted Sound Level [abbreviated dBA or dB(A)] - Frequency weighted Sound Pressure Level approximating the frequency response of the human ear. It is defined as the sound level, in decibels, measured with a sound level meter having the metering characteristics and a frequency weighting specified in the American National Standards Institute Specification for Sound Level Meters, ANSI S 1.4 - 1983. The A-weighting de- emphasizes lower frequency sounds below 1000 Hz (1kHz) and higher frequency sounds above 4 kHz. It emphasizes sounds between 1kHz and 4 kHz. A-weighting is the most generally used measure for traffic and environmental noise throughout the world. Decibel (abbreviated dB) - A decibel is one-tenth of a Bel. It is a measure on a logarithmic scale which indicates the squared ratio of sound pressure to a reference sound pressure (unit for sound pressure level), or the ratio of sound power to a reference sound power (unit for sound power level).

Day-Night Noise Level (Ldn) - A noise level that takes into account all the A-weighted noise energy from a source during 24 hours and weights the nighttime (10 p.m. to 7 a.m.) noise by adding 10 dBA, during that period. Existing Noise Levels - The noise, resulting from the natural and mechanical sources and human activity, considered to be usually present in a particular area.

Leq - The equivalent steady state sound level which in a stated period of time would contain the same acoustical energy as the time-varying sound level during the same period.

Lmax - The highest sound pressure level in a specific time period.

Ln (where n = 1-99; for example, L10, L50 ) - The sound pressure level exceeded n percent of a specific time period. L10 is the level exceeded 10 percent of the time; L50 is the level exceeded 50 percent of the time.

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE A-1 ANC\053120001

ATTACHMENT B Alternative Descriptions

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ATTACHMENT B Alternative Descriptions

The study area, the New Seward Highway corridor from Rabbit Creek Road to 36th Avenue, is shown in Figure 1. The following alternatives are described below:

• No-Build Alternative (through 2035) (required by National Environmental Policy Act)

• Build Alternative 1—Mainline expansion with grade separations and Tudor Road interchange improvements

• Build Alternative 2—Mainline expansion with grade separations and International Airport Road interchange Appendix B of the Preliminary Engineering Report (CH2M HILL, 2004) provides the design criteria for the mainline, frontage roads, ramps, and cross streets. The design criteria were established to conform with guidance provided in Chapter 11 of the Alaska Preconstruction Manual (Alaska Department of Transportation and Public Facilities [DOT&PF], 2003) and the Policy on Geometric Design of Highways and Streets (American Association of State Highway and Transportation Officials [AASHTO], 2000).

No-Build Alternative The No-Build Alternative maintains the existing four-lane divided highway from Rabbit Creek Road to 36th Avenue. No improvements to the mainline, interchanges, or frontage roads within the corridor would be performed. Although major facility improvements would not be made, maintenance of the facilities would require activities such as resurfacing, reconstruction of deteriorated shoulders on frontage roads, and illumination replacement and additions. The No-Build Alternative does include consideration of the effects of projects expected to be built in the corridor during the next 30 years, as specified in the Anchorage Bowl 2025 Long- Range Transportation Plan (Municipality of Anchorage [MOA], DOT&PF, and Anchorage Metropolitan Area Transportation Solutions, 2005), including the following arterial improvements:

• O’Malley Road—widening the segment between New Seward Highway and Lake Otis Parkway from two to four lanes with capacity improvements at major intersections

• Huffman Road—widening the segment between Old Seward Highway and Lake Otis Parkway to provide two travel lanes in each direction

Build Alternative 1—Freeway Expansion with Grade Separations and Tudor Road Interchange Improvements Rabbit Creek Road to O’Malley Road. In this segment, the existing New Seward Highway mainline, which is four lanes (two each traveling north and south) with a center grassed

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE B-1 ANC\053120001 ATTACHMENT B. ALTERNATIVE DESCRIPTIONS

median, remains unchanged. Minor safety and capacity enhancements may be incorporated at the Rabbit Creek, DeArmoun, and Huffman road interchanges. Pedestrian and bicycle improvements consist of a separated multi-use pathway east of New Seward Highway, along the Brayton Drive frontage road. A commuter bicycle route is also included along the right shoulder of Brayton Drive. At the Rabbit Creek Road Elementary School pedestrian overcrossing, Americans with Disabilities Act (ADA) upgrades include ramp access improvements. (Details about pathway and pedestrian facilities are described in the 2003 New Seward Highway Pathway and Pedestrian Facilities report by Land Design North and CH2M HILL.) O’Malley Road to Dimond Boulevard. In this segment, the New Seward Highway mainline is widened from the existing four lanes to six lanes. The grass median is retained. Improvements consisting of a multi-use path and commuter bicycle route along Brayton Drive are included for the east side of the highway. A commuter bicycle route is planned for the west side along the Homer Drive frontage road where a multi-use path already exists. Like the existing path, the proposed path along Brayton Drive is separated from the roadway as much as possible where right-of-way is available. In areas of limited space, the pathway is adjacent to the roadway, separated only by curb and gutter. On the west side, the Homer Drive frontage road is extended south from Dimond Boulevard to O’Malley Road, providing a one-way frontage road system from O’Malley Road to Tudor Road. This segment includes interchange improvements. At O’Malley Road, minor interchange modifications include widening of the southbound ramp exiting from New Seward Highway to two lanes to accommodate transition of the mainline lane from three to two lanes in the southbound direction. A half-diamond interchange constructed at 92nd Avenue2 includes slip ramps between the New Seward Highway mainline and the frontage roads. In the northbound direction, a slip ramp allows traffic from New Seward Highway to “slip” onto Brayton Drive just south of 92nd Avenue. In the southbound direction, a slip ramp allows traffic from Homer Drive to “slip” onto New Seward Highway just south of 92nd Avenue. This grade-separated interchange raises the New Seward Highway mainline on a bridge above 92nd Avenue. The work also includes extension of 92nd Avenue from Homer Drive (west frontage road) to Brayton Drive (east frontage road). This portion of 92nd Avenue is four lanes, providing a through lane in each direction and side-by-side left-turn lanes between intersections with the frontage roads. (The turn lanes in this configuration are constructed inside the through lanes.)

2 The half-diamond interchange at 92nd Avenue actually is constructed on a short segment of road between Old Seward Highway and the New Seward Highway that aligns with 92nd Avenue but is labeled Abbott Road. The alignment of four east- west road segments is generally the same. From east to west, the segments are (1) Abbott Road; (2) Academy Road from Vanguard to Brayton drives; (3) Abbott Road, on the west side of the New Seward Highway and extending to Old Seward Highway; and 92nd Avenue, on the west side of Old Seward Highway. A portion of Abbott Road on the east side of the New Seward Highway deviates from the alignment and curves to join Dimond Boulevard. This report follows the naming practices used in previous transportation documents such as LRTPs and refers to both road segments west of Old Seward Highway as “92nd Avenue.”

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ATTACHMENT B. ALTERNATIVE DESCRIPTIONS

In addition, 92nd Avenue is extended as a two-lane road west to Old Seward Highway, where auxiliary turn lanes are incorporated for the turning movements. Dimond Boulevard to Dowling Road. In this segment, the widened, six-lane New Seward Highway mainline continues. Multi-use pathways are included adjacent to the mainline, and commuter bicycle routes are included along the right shoulders of both Brayton Drive and Homer Drive frontage roads. The pathways are separated from the roadways as much as possible where right-of-way is available. In areas of limited space, the pathways are adjacent to the roadway, separated only by curb and gutter. As part of new grade separations at 76th and 68th avenues, the existing frontage roads are reconstructed to achieve the grade changes. To accommodate a southbound two-lane exit ramp to Dimond Boulevard, the Homer Drive frontage road turns west toward Old Seward Highway at 80th Avenue. Access to the existing businesses farther south on Homer Drive is retained. Homer Drive begins again with the southbound ramp for New Seward Highway. Improvements at the Dimond Boulevard interchange include ramp upgrades, channelization between ramp intersections, and bridge replacement. As part of the ramp upgrades, the southbound ramp exiting New Seward Highway is expanded to two lanes and the ramp intersection is relocated to accommodate the extension of Homer Drive from Dimond Boulevard to O’Malley Road. The work requires rechannelization of Dimond Boulevard to remove the eastbound left-turn pocket to Brayton Drive, where replacement access is provided with the Sandlewood Place extension. Sandlewood Place on the east side of New Seward Highway is reconstructed and extended between Dimond Boulevard and Lore Road (76th Avenue). The new road is 30 feet wide with sidewalks on each side. The extension provides continuity to the north for Brayton Drive and replacement access to the properties along Brayton Drive in conjunction with the removal of the uncontrolled eastbound left-turn pocket from Dimond Boulevard. A new half-diamond interchange joins 76th Avenue with New Seward Highway. The improvement incorporates grade separation and maintains the existing slip ramps to and from the north. New Seward Highway is raised on a bridge over 76th Avenue to allow the extension of 76th Avenue to Brayton Drive. As it passes below New Seward Highway, 76th Avenue consists of four lanes, providing a through lane in each direction and side-by-side left-turn bays between intersections with the frontage roads. Grade separation at 68th Avenue raises New Seward Highway, but does not include ramps for highway access. The extension of 68th Avenue consists of four lanes between Homer and Brayton drives. Dowling Road to Tudor Road. In this segment, the widened, six-lane New Seward Highway mainline continues. Multi-use pathways are included adjacent to the mainline, and commuter bicycle routes are included along the right shoulders of both Brayton and Homer drives. The pathways are separated from the roadways as much as possible where right-of-way is available. In areas of limited space, the pathways are adjacent to the roadway, separated only by curb and gutter. At the Dowling Road interchange, the ramps require reconstruction for the lane added to the outside of the New Seward Highway mainline.

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At International Airport Road, grade separation incorporates raising New Seward Highway by bridge. Extension of International Airport Road connects Homer and Brayton drives. The International Airport Road roadway extension consists of four lanes, providing a through lane in each direction and side-by-side, left-turn auxiliary lanes between intersections with the frontage roads. Between Homer Drive and Old Seward Highway, International Airport Road is reconstructed to three lanes. As part of elevating the mainline over International Airport Road, the bridges over the nearby Campbell Creek for the mainline and frontage roads also are reconstructed. Replacement of the Campbell Creek bridges provides adequate clearance for a future trail extension under New Seward Highway. Tudor Road to 36th Avenue. The existing six-lane New Seward Highway mainline in this segment is basically unchanged. Because the additional through lanes on the mainline match the existing auxiliary lanes south of the 36th Avenue intersection, the intersection does not require reconstruction. Roadway improvements at 36th Avenue may include minor channelization enhancements. Bicycle and pedestrian improvements consist of a new multi-use separated pathway on the west side of the road, adjacent to the mainline, and ADA upgrades for the existing pathways at 36th Avenue and along Tudor Road. For the Tudor Road interchange improvement, two options are being considered:

• Option 1—Upgrade the existing diamond interchange to provide dual left-turn lanes on Tudor Road serving westbound-to-southbound traffic. The addition of a left-turn lane between the ramp intersections requires reconstruction of the Tudor Road bridge.

• Option 2—Construct a loop ramp in the northwest quadrant of the interchange to serve westbound to southbound traffic. This improvement requires acquisition of right-of-way in the northwest quadrant. In addition, this option adds a lane between ramp intersections and requires reconstruction of the Tudor Road bridge. The current five-lane configuration of Tudor Road west to Old Seward Highway is retained. Illumination. From Huffman Road to 36th Avenue, continuous illumination is added to New Seward Highway to augment the existing high-mast lighting at the interchanges. Transportation System Management and Travel Demand Management Components. The transportation system management elements of Build Alternative 1 include advanced traffic management focus at 36th Avenue and selected auxiliary lane treatment for the critical sections of the New Seward Highway mainline where bottlenecks have been identified. The transportation system management elements and deployment of advanced traffic management at the signalized intersections where New Seward Highway ramps terminate and along the mainline are intended to improve traffic flow and reduce congestion. The key transportation system management improvements on the New Seward Highway corridor are as follows:

• Modernization of the traffic signal control system at 24 intersections in the corridor—As a smart corridor, the New Seward Highway corridor incorporates a system to optimize traffic signal system management. The signalized ramp intersections are instrumented with state-of-the-art controller technologies, real-time video monitoring, automated data

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collection, real-time communications to a traffic management center, incident monitoring and management, and adaptive traffic controls responsive to specific traffic conditions. The MOA, which is responsible for all traffic signal operations in Anchorage, controls the traffic management system through its traffic management center.

• Strategic traffic control focus at the intersection of New Seward Highway and 36th Avenue as a network hot spot—Advanced traffic management and engineering initiatives implemented at this intersection include advanced traffic signal timing and traffic engineering approaches consisting of signing, striping, and operation monitoring to maximize intersection throughput and improve safety.

• Use of video traffic monitoring and incident management capabilities on the mainline and at ramp terminals and cross streets

• Access management on the frontage roads and use of these roads as reliever routes for excess congestion and incident conditions

• Provision of park-and-ride facilities near the New Seward Highway freeway, initially at DeArmoun and O’Malley roads for ride-sharing participants and future bus service passengers The initiatives implemented as part of a travel demand management program include the following:

• Expansion of transit service, including vanpool operations

• Promotion of employer-based support and implementation of incentives for shifting travel times

• Encouragement of voluntary travel reduction

• Promotion of expanded use of telecommuting in normal business practices

Build Alternative 2—Freeway Expansion with Grade Separations and International Airport Road Interchange Improvements in the first three segments of the study area—Rabbit Creek Road to O’Malley Road, O’Malley Road to Dimond Boulevard, and Dimond Boulevard to Dowling Road—are the same as those described for Build Alternative 1. The illumination and the transportation system management and travel demand management improvements for Build Alternative 2 are also identical to those under Build Alternative 1. Dowling Road to Tudor Road (with International Airport Road interchange). For this segment, the mainline and pathway improvements are the same as those for Build Alternative 1. At the Dowling Road interchange, the northern entrance and exit ramps connecting Dowling Road to New Seward Highway are removed. (AASHTO recommends 1-mile spacing between intersections.) As a result of this change, southbound traffic on New Seward Highway traveling to Dowling Road must exit at the new International Airport Road interchange and travel on Homer Drive south to Dowling Road. Northbound traffic

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from Dowling Road travels on Brayton Drive to International Airport Road, where a ramp is available to enter New Seward Highway. The new interchange at International Airport Road consists of a diamond configuration. New Seward Highway is raised over International Airport Road on a bridge. International Airport Road is extended east to meet Brayton Drive and is four lanes, providing a through lane in each direction and side-by-side left-turn lanes between intersections with the frontage roads. International Airport Road continues as a three-lane road from New Seward Highway to Old Seward Highway where it joins the existing five-lane configuration. Elevating the New Seward Highway mainline over International Airport Road also requires replacement of the bridges over Campbell Creek. Replacement of the Campbell Creek bridges will provide adequate clearance for a future trail extension under New Seward Highway, Brayton Drive, and Homer Drive. Tudor Road to 36th Avenue. The New Seward Highway mainline, pathway, and 36th Avenue intersection improvements are the same as those described for Build Alternative 1. Two options are considered for use at the Tudor Road interchange:

• Option 1—The existing diamond interchange is upgraded to provide dual left-turn lanes on Tudor Road, serving westbound-to-southbound traffic. The addition of a left-turn lane between the ramp intersections requires reconstruction of the Tudor Road bridge. Also, to accommodate the International Airport Road interchange, the southbound ramp for traffic entering New Seward Highway from Tudor Road and the northbound ramp for traffic exiting New Seward Highway at Tudor Road are removed.

• Option 2—To accommodate the International Airport Road interchange, the southbound ramp for traffic entering New Seward Highway from Tudor Road and the northbound ramp for traffic exiting New Seward Highway at Tudor Road are removed. To serve northbound traffic from Brayton Drive to Tudor Road, “hook” ramps are constructed in the northeast and southeast quadrants of the Tudor Road and New Seward Highway interchange. This configuration provides adequate distance between the two ramp intersections with Tudor Road to maintain traffic flow and eliminates the need to replace the Tudor Road bridge. The current four-lane configuration of Tudor Road west to Old Seward Highway is retained.

References American Association of State Highway and Transportation Officials. 2000. Policy on Geometric Design of Highways and Streets. Alaska Department of Transportation and Public Facilities. June 16, 2003. Alaska Preconstruction Manual. CH2M HILL. September 2004. New Seward Highway, Rabbit Creek to 36th Avenue, Preliminary Engineering Report.

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Municipality of Anchorage, Alaska Department of Transportation and Public Facilities, and Anchorage Metropolitan Area Transportation Solutions. December 2005. Anchorage Bowl 2025 Long-Range Transportation Plan.

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ATTACHMENT C Onsite Noise Level Measurement Data

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001

ATTACHMENT D Traffic Data Summary

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001

ATTACHMENT D Traffic Data Summary

Traffic Volume Distribution

Vehicle Distribution (%) Transportation System Component Cars Medium Trucks Heavy Trucks

Highway 95 2.5 2.5

Ramps 95 2.5 2.5

Frontage Roads 94 3 3

Cross Streets 94 3 3 Source: CH2M HILL

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ATTACHMENT E Noise Abatement Checklists

NOISE ANALYSIS, NEW SEWARD HIGHWAY RABBIT CREEK TO 36TH AVENUE ANC\053120001