About 70 people attended the Washington State Department of Transportation's open house Thursday evening at Tillicum Elementary School in Lakewood to go over the details of the Interstate 5 widening project with rebuilt Berkeley and Thorne Lane interchanges.

The $495 million I-5 project runs along Joint Base Lewis-McChord and is scheduled to be complete in 2025.

"A lot of people are interested in the closures that will occur, but most people are just excited to get the second stage of the project started," said Cara Mitchell, a spokeswoman with WSDOT. "Of course, most of the closures will take place at night or over the weekends. Our weather has a lot of impact on our schedules, but we will communicate as much as we can when closures are pending."

Twelve representatives from WSDOT; Amtrak; and Guy F. Atkinson Construction LLC, the company that was awarded the contract, were on hand at the open house to make presentations and to answer questions.

"People should see us digging dirt on Berkeley very soon," said Jim Zusy, project manager for Atkinson. "It's a design-build project, so as soon as the plans are done and approved, we're out the door ready to go."

This is the second of four projects in the area and is intended to help relieve congestion and improve safety by reducing collisions. The first stage was adding an auxiliary lane between Mounts Rd. and Center Dr.

The second stage, which will be done in 2021, will increase freeway capacity by adding a lane in both directions from just north of Steilacoom-DuPont Rd. (exit 119 by the DuPont Gate on JBLM) to Thorne Lane in Lakewood (exit 123 near the Logistics Center Gate on JBLM).

Auxiliary lanes will also be added between Berkeley St. (exit 123 near the Madigan Gate) and Gravelly Lake Dr. (exit 124 located between the McChord Field Housing and the Logistics Center gates). New interchanges at Thorne Ln. and Berkeley St. will be constructed over the existing high-speed rail line, which eliminates potential conflicts with trains. The new overpasses will be built adjacent to the existing structures, which minimizes closures during construction.

Other impacts throughout the duration of the project include:

• Night lane closures

• Narrowed lanes on I-5

• Some minor night impacts to city streets

• Partial night ramp closures and some total night closures of mainline I-5 during bridge demolition and girder placement

• Weekend closures and one extended closure of Berkeley ramps to construct new overpass and Berkeley on-ramp to northbound I-5

• One weekend closure of the Madigan Gate

• Extended closure of Union Ave. at Thorne Ln. to raise profile of Union Ave. to meet height of new overpass.

For more information about the project, visit: wsdot.wa.gov/Projects/I5/steilacoomdupontrdtothornelnimprove/default.htm.