Why is there so much congestion?
Interstate 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, conducted in 2014, WSDOT conducted a comprehensive multi-modal corridor alternative analysis. In this effort, WSDOT evaluated alternatives other than adding lanes to I-5 that could improve mobility along the corridor. Public involvement was an important element of Phase 2.
In January 2014, WSDOT conducted an origin-destination study. The origin-destination study better identified the nature of local trips and regional traffic on and near Interstate 5 between Mounts Road and State Route 512. 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 were further evaluated along with those developed during the multi-modal Alternatives Analysis. Alternative "packages" including combinations of transit services, local road improvements and I-5 mainline and interchange improvements were defined and evaluated. Thirteen alternative "packages" were modeled for performance and evaluated for potential environmental impacts as well as implementation characteristics.
Performance criteria during the weekday p.m. peak travel period that were modeled and scored include:
- Traffic speed.
- Hours of congestion.
- Travel time between Mounts Road and Bridgeport Way.
- Number of people that could move through the corridor.
- Percent of total person demand that could move through the corridor.
- Potential person trips using HOV's (including vanpools and transit).
Implementation characteristics that were evaluated and scored include:
- Relative cost to implement the alternative.
- Amount of new Right-of-Way needed.
- Ability to build the alternative in stages.
The result was proposed alternatives (pdf 8.5 mb) that will be advanced into the NEPA environmental study process. Phased implementation of improvements is proposed with an initial or "opening year" alternative and a "future" alternative.
The proposed Initial Phase of improvements include:
- Rebuilding the Thorne Lane interchange.
- Rebuilding the Berkeley Street interchange.
- Add one HOV lane to each direction of I-5 from Thorne Lane to Steilacoom-DuPont Road.
- Rebuilding the Steilacoom-DuPont Road interchange.
- Possible local connection from Gravelly Lake Drive to Thorne Lane.
- Bike/Pedestrian path along the I-5 corridor.
The proposed future phase would include:
- Add one additional lane to each direction of I-5. Two lanes each direction would be Express Lanes restricted to through traffic only. Traffic entering or exiting I-5 in the JBLM area would use the outer three lanes.
- Revisions to Main Gate interchange.
In Phase 3 of the study, NEPA environmental studies and documentation will be conducted for the proposed alternatives. WSDOT and other stakeholders will also evaluate proposed revisions to interchanges and document them in an Interchange Justification Report (IJR).
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.
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 Data for PINs 000513A & 300596S|
||Amount ($ in thousands)|
|2003 Gas Tax (Nickel Funding)
|2005 Gas Tax (TPA)
|Pre-Existing Funds (PEF)
How can I get more information?
Olympic Region Plans Engineer
Claudia Bingham Baker
WSDOT Communications Manager