Locust Way - Bridge 504

October 2016 Update

The project was initially expected to be completed by mid-October 2016, but due to unforeseen circumstances, the bridge is scheduled to re-open in mid-to-late November 2016. The construction delay stems from production constraints of the steel pipe piling that is part of the foundation of the bridge. Crews from McClure and Sons, Inc. have been working Saturdays to make up for the lost time, but unfortunately not enough time has been recovered. 

To assist in relieving traffic in the area caused by school drop-off and pick-up near the project site, Snohomish County Public Works has hired an off-duty police officer to direct traffic at the intersection of Carter Road and Lockwood Road. The police officer will continue to direct traffic during the morning and afternoon commute periods for the duration of the project, Monday through Friday.

Locust Way will remain closed between 231st Street SW and Barker Road to all vehicles, bicycles, and pedestrians until the completion of the project.


Bridge 504 carries Locust Way over Swamp Creek. It is only two lanes and located between Bothell and Brier. Built originally in 1936 and rebuilt in 1958 and 1988, it will be replaced in summer 2016.

To meet current federal bridge standards, Snohomish County is replacing the bridge with a new structure that is longer, wider, and several feet higher. The bridge will be lengthened from 41 to 70 feet and widened from 23 to 47 feet. The new bridge will have two driving lanes, bike lanes, and sidewalks. Railings and guardrails will be installed where needed.

The new bridge foundations will be placed outside of the existing creek channel; crews will also remove the center pier, which currently catches debris that can cause damage to the bridge.

Runoff from the new bridge and portions of the road will enter a new storm water system and discharge to a bioswale, a type of biofilter designed to remove silt and pollution from surface runoff by directing the water through a drainage course filled with vegetation.

Environmental Review

An environmental review of the bridge replacement project was completed in compliance with the State Environmental Policy Act (SEPA). SEPA requires that all state and local agencies identify and evaluate the environmental impacts of their land use decisions. An environmental checklist was prepared July 30, 2012. A Notice of Determination of Nonsignificance (DNS) and Land Disturbing Activity (LDA) Permit have been issued.

These documents are available by viewing the links below or from Snohomish County public works during normal business hours:


Construction is currently underway for this project and is expected to be completed by mid-to-late November 2016.