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I-5 - JBLM Vicinity - Congestion Relief Study

Why is there so much congestion?

Traffic on Interstate 5 in LakewoodInterstate 5 is a national highway of strategic importance. It moves goods and people between two borders and links major cities. It is a critical corridor for military use. Over the past several years, traffic has increased along the entire I-5 corridor, and nowhere has that increase been more noticeable than in south Pierce County through the Joint Base Lewis-McChord (JBLM) vicinity.

A combination of factors have contributed to the traffic growth through the area. Large businesses have moved in. JBLM and Camp Murray have expanded, and the communities of Lakewood, DuPont and Steilacoom have continued to develop. Each change has added demand on the already-crowded I-5 corridor. Motorists now see traffic congestion on a daily basis, especially during peak commute hours. Because secured military bases are located on both sides of I-5, alternate routes involve using perimeter roads around the bases. Those routes are neither convenient nor able to manage high volumes of traffic.

What is WSDOT doing about it?

In 2013, a joint I-5 corridor planning study was initiated involving WSDOT, JBLM, FHWA and local jurisdictions. The study is evaluating the best way to improve transportation through the JBLM vicinity. The task of the planning study is to define improvements that could relieve congestion on I-5 from Center Drive to Gravelly Lake Drive, with a focus on the interchanges at the Steilacoom-DuPont exit (#119), 41st Division Drive/Main Gate exit (#120), Berkeley Street exit (#122) and the Thorne Lane exit (#123).

Specifically, the study addresses options to:

  • relieve congestion on I-5
  • improve system efficiency
  • enhance mobility
  • improve safety and operations
  • increase transit and alternative commute opportunities

This work is being performed in three phases. Phase 1 conducted a Corridor Feasibility Study. You can read the full report and the summary report linked below:

During Phase 2, WSDOT is conducting a comprehensive multi-modal corridor alternative analysis. In this effort, WSDOT will evaluate alternatives off I-5 that could improve mobility along the corridor. Public involvement is an important element of Phase 2.
In January 2014, WSDOT conducted an origin-destination study. The origin-destination study will better identify the nature of local trips and regional traffic on and near Interstate 5 between Center Drive and Gravelly Lake Drive. This study was documented in a report on Travel Patterns and Characteristics along the I-5 corridor in the JBLM vicinity.

The report describing the development and screening of multimodal options for the corridor can be accessed at the following link:

Between July and November 2014, alternatives advanced from Phase 1 will be further evaluated along with those developed during the multi-modal Alternatives Analysis. The result will be proposed alternatives that will be advanced into the NEPA environmental study process.

In Phase 3, NEPA environmental studies and documentation will be conducted for potential alternatives. WSDOT and other stakeholders will evaluate proposed revisions to interchanges and document them in an Interchange Justification Report (IJR).

Map of study area

 View full-size image (pdf 2.18mb)

Why are studies needed?

The planning study will result in a NEPA environmental document and an IJR, which is a study required by federal law used to justify revisions to highway interchanges. The IJR documents the design of the preferred alternative, the planning process, the evaluation of considered alternatives, and the support and justification for requesting an access revision. With the results from the report, project stakeholders can take action to implement the preferred solutions.

What will the completed study include?

  • National Environmental Policy Act (NEPA) environmental documentation for proposed corridor improvements and preliminary engineering for the highest priority improvements.
  • A completed Interchange Justification Report for revisions to the four focus-area interchanges. 

Cost Estimate

This corridor study evaluates a wide range of potential improvements, including alternatives for revisions to Interstate 5, four interchanges, arterial roadways off of I-5, transit and transportation demand management strategies. The cost estimates for implementing elements of these alternatives range from fairly low for specific items, to extremely high for a large package of capital improvements along several miles of I-5.

The estimated cost of potential improvements is an important factor in decision making. Estimated costs are based on proposed physical revisions, the quantities of materials and labor to implement them, purchasing property for additional right of way and the expected market costs of acquiring those. The starting point is to determine what the proposed physical revisions are.

The 2010 study, I-5 Transportation Alternatives Analysis and Traffic Operations Model, recommended alternatives for revisions at four interchanges in the JBLM area. An Opinion of Costs was prepared for those revisions. These recommendations are included in the range of alternatives being considered for the corridor.

During this study, as the range of alternatives is narrowed toward defining a preferred alternative for improvements, further design engineering will be conducted and estimated costs prepared.

What is happening in the mean time?

While the planning study is underway, some construction is already taking place in the corridor, and more construction is scheduled to start soon.  The construction projects will provide short-term improvements to help relieve congestion.  Specifically, crews will: 

  • Install ramp meters
  • Widen ramp lanes
  • Add a ramp lane and auxiliary lane
  • Install data collection stations
  • Install Intelligent Transportation System improvements

View a map of these preliminary project features. 

Financial Information

Financial Data for PINs 000513A & 300596S
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $6,502
Total $6,502

How can I get more information?

Bill Elliott
Olympic Region Plans Engineer

Claudia Bingham Baker
WSDOT Communications Manager