SR 99/Spokane Street Bridge - Expansion Joint Modification

Nearly 58,000 vehicles travel SR 99 at the Spokane Street bridge daily, up 14% from 2022. The bridge was first built in 1959 and rebuilt in 2013.

To preserve the bridge, we will replace 13 expansion joints with a watertight joint seal system and rehabilitate the bridge’s drainage system so the bridge deck drains properly after the watertight joints are installed.

Expansion joints run across the width of the freeway allowing sections to expand and contract with weather and to flex under the weight of heavy vehicles. If joints are not replaced, the bridge will not flex properly. This will cause undue stress on the structure and reduce the overall lifespan of the bridge. Replacing these expansion joints during scheduled closures allows people to plan ahead and reduces the chances a joint will break and require an emergency closure.