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I-5 - Mounts Road to Thorne Ln I/C - Corridor Improvements

Status

November 2017

 

Why is WSDOT proposing to expand Interstate 5 through the Joint Base Lewis-McChord corridor?
Originally built in the 1950s, 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.

The recommended improvements advanced forward from a joint planning study are:

  • Add one lane to southbound I-5 from Thorne Lane to the DuPont area.
  • Add one lane to northbound I-5 from Mounts Road to Thorne Lane.  
  • Rebuild interchanges at Thorne Lane and Berkeley Street using roundabouts.
  • Build a new local connector road between Gravelly Lake Drive and Thorne Lane.
  • Build a bicycle/pedestrian path along the I-5 corridor.
  • Improvements to the Steilacoom-DuPont Road interchanges are still being defined.

In July 2015, the Washington State Legislature included $495 million to fund the I-5 Mounts Road to Thorne Lane Interchange - Corridor Improvements project, as part of the Connecting Washington transportation revenue package. The project is funded through a 10 year period, from 2015-2025.

The End Result
The proposed changes would reduce chronic traffic congestion through the JBLM corridor. New interchanges that incorporate roundabouts instead of signals would improve traffic flow and reduce the potential for collisions.

Currently the only access into the Tillicum community is via I-5. The proposed Gravelly-Thorne connector would give the neighborhoods of Tillicum and Woodbrook access to Lakewood without using I-5. The proposed shared use path for bicycles and pedestrians would give Woodbrook and Tillicum residents a multi-modal option to commute to work or school.

Project Benefits
 
Congestion Relief: Interstate 5 and surrounding local arterial roads would experience congestion relief and reduced delays. The Gravelly-Thorne connector would provide local access to Tillicum and Woodbrook neighborhoods without using I-5. The bicycle/pedestrian path gives commuters a multi-modal option to commute to work, and connects communities along the I-5 corridor.

Safety: New lanes that add capacity to the freeway will reduce collisions along the corridor. The new interchange at Thorne Lane, Berkeley Street on I-5 would improve traffic flow and enhance safety with the use of roundabouts.

What is the project timeline?

  • In July 2015, the Washington State Legislature included $495 Million for the I-5 Mounts Road to Thorne Lane Interchange - Corridor Improvements project, as part of the Connecting Washington transportation-revenue package.
  • I-5 - Mounts Road to Center Drive - Auxiliary Lane Extension construction is occurring in summer 2017. Northbound I-5 will be widened between Mounts Road and Center Drive. An added lane will be operated as an auxiliary lane until later stages are completed. This work has independent utility, meaning it provides benefits to the traveling public independent of the other project elements.

On May 23, 2017, the U.S. Department of Transportation Federal Highway Administration issued a Finding Of No Significant Impact (FONSI) for the Interstate 5 JBLM Congestion Relief Project Environmental Assessment.

Next steps for the project involves permitting, right-of-way acquisition, and the competitive bidding process. Project construction will then occur.

  • North End Construction, scheduled to begin in 2018, would rebuild the Thorne Lane and Berkeley Street interchanges, and add a fourth lane to I-5 in each direction from Thorne Lane to Steilacoom-DuPont Road.
  • South End Construction, scheduled to begin in 2020, will build improvements between Mounts Road (Exit 116) and Steilacoom-DuPont Road (Exit 119). Improvements to the Steilacoom-DuPont Road interchange are still being defined.

All dates are preliminary and subject to change. 

Financial Information

Financial Data for PIN BM00100R
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $0
CWA $494,418
Total $494,418

Project signage will reflect the cost of construction engineering, project bid award and sales tax.

How can I get more information?
Contact:
Bill Elliott
WSDOT JBLM Project Manager
360-357-2735

Claudia Bingham Baker
WSDOT Communications Manager
360-357-2789

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