SR 509 Completion Project - South 216th Bridge Construction

S 216th Bridge construction

Replacing the existing S 216th Bridge is necessary to construct the ramps and collector-distributor lanes that will connect SR 509 to I-5. Construction of the new S 216th Street Bridge over I-5 in SeaTac will restrict pedestrian access on one of the few places in the area to cross I-5 on foot. Pedestrian restrictions won’t begin until late 2021 (Stage 2 below), but we want to make sure those who use the bridge know about construction in advance. We will provide more information about pedestrian restrictions and potential alternatives for access during those restrictions as we get closer to construction.

Construction Staging

The bridge will be constructed in three stages. Each stage will require restrictions on the existing bridge, which include:

S 216th Bridge construction stage 1 graphic

During Stage 1, the bridge will remain open to westbound traffic; eastbound traffic can use S 200th Street and SR 516 to cross I-5. Pedestrian access will be provided on one side of the bridge. Construction duration – Approximately one year, from late 2020 to late 2021.

S. 216th Bridge construction stage 2 graphic

During Stage 2, the bridge will be open to one lane of traffic in each direction (same as today). There will be extended periods of no pedestrian access across the bridge. Construction duration – Approximately one year, from late 2021 to late 2022.

S 216th Bridge construction stage 3 graphic

During Stage 3, the bridge will be open to one lane of traffic in each direction (same as today). Pedestrian access will be provided on one side of the bridge. Construction duration – Approximately three months, from late 2022 to early 2023.

Completed S 216th Bridge graphic

When complete, the new bridge will include 6-foot-wide sidewalks and 5-foot-wide bike lanes on both sides of the bridge.