SR 524 - Locust & Larch Way - Intersection Improvements - Complete April 2019


In spring 2019, contractor crews finished building two roundabouts on State Route 524 at Locust Way and Larch Way in an effort to reduce the risk and severity of collisions at those intersections. ​Prior to the roundabouts being built, these intersections had collision rates higher than the state average when compared to similar highways. There were 81 collisions at these intersections from 2011 through 2015, approximately 16 each year. There were 36 injuries to drivers and passengers as the result of these collisions. With approximately 16,000 trips on this stretch of SR 524 each day, safety improvements were necessary. There may be a slight improvement in through-traffic because cars will no longer need to block traffic to make a left turn.

Congestion relief will require a separately-funded project
Widening this section of SR 524 was included on the Regional Transportation Investment District list of projects for funding on the 2007 Proposition 1 ballot measure. Since voters defeated the measure, no funding has been identified to complete the widening of SR 524. A congestion-relief project will require widening the road, which is a more substantial project that we can accommodate with the current funding level. 

Project benefits

WSDOT considered six options for these intersections, but most required a wider highway to implement them. Widening will cost substantially more money than currently available because widening will need to address two creeks, a wetland, a narrow bridge built in 1935, right of way, and the I-405 bridge columns. Learn more about the options studied by WSDOT. With their proven history of reducing collisions, roundabouts were ultimately selected for this safety improvement project.


Pre-Existing Funds (PEF): $5,120,000

Total: $5,120,000


Northwest Region Communications
15700 Dayton Ave. N.
Seattle, WA 98133


A small map showing the location of Locust and Larch Ways on SR 524 near Lynnwood and Bothell, Washington.

Aerial view of the new roundabout at SR 524 and Larch Way

Crews finish new roundabouts on SR 524 at Locust and Larch ways
View larger photos