Q: Says here that WSDOT is going to add lanes to Interstate 5 near JBLM. What’s the catch?
A: Roundabouts. Well, not quite. We’ll get back to them in a moment, though.
The actual catch is that it’s going to be another 2 1/2 years of road construction along I-5.
Still, adding a fourth lane each way through the Joint Base Lewis-McChord stretch of the freeway is a promising development, especially for commuters who develop a tic when the phrase “base traffic” is uttered.
The project starts in earnest the second week of October with some shifted lanes and construction barriers erected near the Berkeley Street exit, according to Cara Mitchell, a spokeswoman with the state Department of Transportation. You’ll start to notice some narrower lanes through there at the same time.
When work wraps up by the summer of 2021, here’s what the project should look like:
• Four lanes of traffic will go north and south on I-5 from the Steilacoom-DuPont Road to Thorne Lane exits.
• An exit-only lane will be added on northbound I-5 between the Berkeley Street and Gravelly Lake Drive exits
• Exit-only lanes will be added on southbound I-5 between the Gravelly Lake Drive and Thorne Lane exits and between the Berkeley Street and Joint Base Lewis-McChord main gate exits.
• New overpasses will be built for the Berkeley Street and Thorne Lane exits, removing at-grade railroad crossings.
• The southbound I-5 exits to Berkeley Street and Thorne Lane will share an off-ramp and a collector-distributor lane.
• Big-rig friendly roundabouts will be added to the Thorne Lane interchanges.
Those roundabouts have 75 percent fewer injury crashes than intersections regulated with traffic lights or stop signs, Mitchell says.
“We don’t have any concerns about using them,” she says.
The roundabouts were a part of the state’s preliminary design for redoing the Berkeley Street and Thorne Lane interchanges, Mitchell says, though builder Atkinson Construction added more of the exit-only lanes as part of its bid design.
Drivers who have questions about $243 million project can attend an open house from 4:30-7 p.m. Oct. 25 at Tillicum Elementary School, 8514 Maple St. SW.
