A $494 million road-widening project for I-5 near a Washington state military base was approved by the state Legislature. Much of the project will be funded by an 11.9-cent-per-gallon gas tax increase.
The expansion project will take place near Washington’s largest workplace, the Joint Base Lewis-McChord, which sees an average of 120,000 vehicles per day.
The six-year project calls for adding at least eight lanes of traffic including a northbound lane from Mounts Road to Steilacoom-DuPont Road and a lane in each direction from that point to Thorne. The project will mainly affect drivers between Olympia and Tacoma, Wash.
The expansion also requires demolishing the overpasses that carry Thorne, Berkeley and Steilacoom-Dupont over I-5, bridges that aren’t wide enough to allow for an eight-lane interstate.
Three new bridges will become part of major new intersections known as “dog bone” interchanges because of their shape, which connects two roundabouts.
Preliminary work such as permitting and design is to be done so crews can begin working in 2017. The plan is to open the northern part of the highway in 2020 and finish the southern part in 2023.
