Background and Overview Document

Click on the following links to view Background and Overview Document in PDF format:

Executive Summary through Section 3, Development Characteristics and Corridor Travel Patterns (PDF, 878KB)

Section 4, Existing Transportation System through Section 11, References (PDF, 9.4MB)

Appendix A, Transit Alternatives Analysis (PDF, 1MB)

Appendix B, Accidents Occurring on Each ADOT&PF Defined Coordinated Data System (CDS) Route (PDF, 100KB)


Preliminary Purpose and Need Statement

Purpose of the Proposed Action

The purpose of this study is to provide a list of alternatives for improving the New Seward Highway transportation corridor that will:

  • Integrate Community Policy and Planning
  • Improve East/West Connectivity and Linkage
  • Address the Problem of Congestion
  • Improve Public Safety
  • Improve Public Transit
  • Consider Traffic Management Options
  • Improve Bicycle and Pedestrian Pathways
  • Ensure Conformity with Clean Air Regulations
  • Improve Freight Mobility
  • Address Roadway Deficiencies

The process of preparing an environmental document will provide public comment and meaningful involvement to assist in formulating a list of alternative modal improvements to be considered for the New Seward Highway.

History and Background
The New Seward Highway is part of the National Highway System and a vital link in Alaska's transportation system. Construction of a four-lane divided highway with at-grade intersections began in 1967 and was completed in 1971. The new facility alignment starts from around 30th Avenue to Potter's Marsh where it rejoins the original Seward Highway alignment. A progression of improvements to the new alignment included the addition of interchanges at Tudor Road, Dowling Road, Dimond Boulevard, O'Malley Road, Huffman Road, DeArmoun Road, and Rabbit Creek Road. The facility is now controlled access from Rabbit Creek Road to Tudor Road. North of Tudor, the NSH transitions to an at-grade intersection at 36th Avenue where the character of both the highway and surrounding development density changes.

Need for the Proposed Action
During the last decade the Anchorage Bowl has experienced a steady growth rate and population increase of 14.5%. Projected population growth figures for Anchorage show a steady increase through the design period of 2025. The areas of the Bowl receiving the greatest amount of growth are the central and southeast sub-planning areas. The NSH is the main north-south corridor serving these areas. During peak AM and PM travel periods, traffic volumes increase and the pace of traffic slows to a crawl.

This study will determine whether or not the constant stop and start action caused by this congestion decreases air quality and is a contributing factor to the likelihood of traffic accidents. The proposed action is needed to address these effects, and to help enhance intermodal relationships. This study will identify solutions to improve operational efficiency of both the north/south system and east/west arterials, and facilitate coordination among other transportation modes, thus reducing these effects.

Modal Alternatives

Scoping Summary Report

Executive Summary

The Alaska Department of Transportation and Public Facilities (ADOT&PF) in collaboration with the Municipality of Anchorage (MOA) has initiated planning studies to evaluate ways to meet current and future travel needs in the New Seward Highway (NSH) corridor. The planning studies are guided by a transportation planning process framework known as a Major Investment Study (MIS) as well as by the principles stipulated in the National Environmental Policy Act (NEPA), which applies to federally aided transportation investments. The MIS and NEPA process seeks objective assessments of candidates' solutions drawn from multimodal transportation alternatives.

This document presents findings concerning the performance of an array of modal alternatives in meeting current and future transportation needs in the NSH corridor area. Its purpose is to inform a policy decision by ADOT&PF and the Anchorage Metropolitan Area Transportation Study (AMATS) Policy Committee regarding which of the alternatives merit continued planning, engineering, and environmental impact assessment and which alternatives should be dropped from further consideration.

Alternatives Considered for the NSH Corridor MIS

Eleven primary alternatives were identified and evaluated in the NSH MIS analysis. They are:

  • A 9.4-mile light rail transit guideway and feeder bus system from downtown Anchorage to DeArmoun Road
  • A commuter rail passenger service on 13.9 miles of the Alaska Railroad Corporation's (ARRC) tracks from Ship Creek in Downtown Anchorage to Potter Valley Road, with connecting feeder bus services
  • An express bus system on the NSH with local service collection and distribution and park-and-ride lots adjacent to the freeway
  • Standalone bus transit with significantly increased service frequency, integrated with two new town center developments along Lake Otis Parkway
  • A Transportation System Management/Travel Demand Management (TSM/TDM) alternative that incorporates an array of transportation operations and demand mitigation programs and initiatives
  • An NSH "No-Build" or "No Action" alternative that limits highway improvements in the NSH corridor to those presently underway or firmly funded and committed
  • A High Occupancy Vehicle (HOV) lane alternative that expands the NSH from 4 to 6 lanes but restricts use of the added lanes to vehicles with two or more persons during peak commuting hours, together with updates in design standards and frontage roads
  • A Reversible Lane alternative that expands the NSH with a reversible lane or roadway that would operate inbound for the morning peak commute and outbound for the afternoon peak commute, with updates in design standards and frontage roads
  • No widening of the NSH but the addition of underpasses or overpasses at 68th, 76th, and 92nd Avenues
  • An alternative that expands the NSH from 4 to 6 lanes, updates design standards and frontage roads, and includes underpasses or overpasses at 68th, 76th, or 92nd Avenue
  • An NSH alternative with an International Airport Road interchange added for connection to the Ted Stevens Anchorage International Airport, including underpasses or overpasses at 68th, 76th, and 92nd Avenues, with updated design standards and frontage roads
Recommended Action
The key decision to be made at this time is which alternatives should go forward for more detailed planning, engineering, and environmental assessment. Based upon background and conditions studies, public involvement input, and analytical evaluations, the following actions are recommended regarding alternatives to be carried forward in the NEPA evaluation process:

  • Continue evaluation of the NSH No-Build alternative as required in NEPA procedures for a benchmark comparison against other alternatives.
  • Continue evaluation of the HOV lane alternative for feasibility with complementary intermodal integration of bus transit improvements and TSM/TDM strategies.
  • Continue evaluation of the NSH Build 6-lane expansion alternative (with east-west crossing alternative) with refinements to address capacity-demand balance and spot improvements.
  • Continue evaluation of the NSH 6-lane expansion alternative (with east-west crossing alternative) with an International Airport Road interchange and refinements to address capacity-demand balance and spot improvements.
  • Continue evaluation of bus transit and TSM/TDM strategies as companion elements of an integrated multimodal transportation solution that includes NSH improvements.
  • Discontinue further evaluation of light rail transit and commuter rail service.
  • Discontinue further evaluation of standalone express bus service on NSH, standalone bus transit, and standalone TSM/TDM alternatives.
  • Discontinue further evaluation of Reversible Lane alternative.
Basis for Recommended Action

As part of the formalized MIS planning process, the 11 alternatives outlined above were analyzed and screened for their effectiveness in meeting corridor transportation needs and conformity with community and transportation plans.

Table ES-1 summarizes the key analysis findings for each of the 11 alternatives. The table synopsis is derived from the analytical steps and methods described below.

Existing travel and travel forecasts for year 2023 serve as the quantitative benchmarks for corridor and regional transportation demand. Estimates of transit ridership and TSM/TDM market penetration were made to gauge the effectiveness of these alternatives. Regional highway traffic assignments for 2023 were made to determine traffic volumes, congestion locations, and level of service (LOS) measures for network roadway segments.

As standalone concept alternatives, the light rail, commuter rail service, express bus on NSH, bus transit, and TSM/TDM strategies-including bicycle/pedestrian subsets-will not resolve transportation needs in the corridor. Highway improvements are required to address travel demand and transportation plan performance objectives.

Continued engineering and environmental assessment evaluation as required in the NEPA process is recommended for the NSH Build alternative as the primary concept and the NSH No-Build alternative as the benchmark baseline. The HOV lane alternative should also receive further evaluation in conjunction with complementary intermodal integration of bus transit improvements and TSM/TDM strategies.

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