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. The project would widen seven miles of Interstate 5 in Pierce County, from DuPont to Lakewood, adding an HOV lane in each direction. The proposed changes would reduce chronic traffic congestion through the JBLM corridor. To widen I-5, new interchanges are being reconstructed using roundabouts instead of signals to improve traffic flow and reduce the potential for collisions. The new interchanges are grade-separated from the existing rail line, reducing conflicts with trains.
The funding for the project spans over a 10 year period. The funding schedule and right-of-way acquisition play a big part in determining when construction occurs.
Based on the funding schedule, the I-5 Mounts Road to Thorne Ln I/C Corridor Improvements project is broken up into 4 separate construction projects:
During construction, travelers will see:
- Reduced speed limit in work zone
- Overnight ramp and lane closures
- Shifted lanes
- Long-term ramp closures and detours