New Thurston County roundabout coming to highway with history of T-bone crashes
Traffic will be slowed on state Route 510 at Rockcress Drive near Lacey starting Friday evening.
Drivers can expect lane reductions from 7 p.m. Friday to 6 a.m. Saturday, according to the Washington State Department of Transportation.
State Route 510 is a key highway that connects to Yelm and Interstate 5 in east Thurston County. The work zone is reportedly being set up so crews can conduct “exploratory drilling” as part of a roundabout project at the intersection of SR 510, McAllister Court Southeast and Rockcress Drive. Flaggers are expected to direct drivers through one lane of alternating traffic, per WSDOT.
Construction for the single-lane roundabout started this spring and is scheduled to be completed by Spring 2027. WSDOT conducted a study of the intersection in 2022 after noting a history of collisions, typically T-bone crashes.
“A traffic signal doesn’t eliminate the possibility of those types of collisions,” the WSDOT website states. “A traffic signal may also increase the number of rear-end crashes. Roundabouts also help promote traffic flow.”
The agency hopes the roundabout will reduce the number of conflict points, areas on a road where traffic crosses, merges or diverges.
The WSDOT project webpage did not list the cost of the project as of Thursday morning. It only says the roundabout is funded by the U.S. Department of Transportation Highway Safety Improvement Program, a federal program that aims to reduce traffic fatalities and serious injuries on public roads.
The Olympian has asked WSDOT to share the cost of the project.
Crews are planning to work on the roundabout in stages, WSDOT says. During these times, crews will shift lanes and reduce the speed limit as necessary. The public can see traffic impacts on the WSDOT real-time map online.
Once completed, the new roundabout will be the sixth one built on state Route 510 between Lacey and Yelm, according to WSDOT.
The agency says the most recently completed roundabouts are at the intersection with Yelm Highway Southeast and the nearby intersection with Reservation Road.
