WSDOT is studying I-90 tolls as a method to help balance traffic across the Lake and raise needed revenue to complete the SR 520 Project. I-90 and SR 520 form the Cross-Lake Washington Corridor, two parallel highways that operate as one system to connect the region’s major employment and population centers by bridging Lake Washington, a 22 mile long (north-south) body of water. The two bridges are functionally dependent on each other to move people and goods. If one bridge shuts down, the other carries the brunt of the traffic diversion. If the necessary improvements on SR 520 are not completed, there is a 20% risk over roughly the next 50 years that a catastrophic event will shut down SR 520, shifting most cross-lake travel to I-90, and virtually shutting down the regional transportation system.
In fall 2012, WSDOT analyzed travel data for over 40,000 license plates crossing the I-90 bridges. We matched vehicles to addresses based on registration information from Department of Licensing records. With no other identifying information, analysts were able to use this information to learn more about who uses the I-90 bridges, where they may be coming from, and how tolls could potentially affect them.
This map shows the preliminary toll-point locations WSDOT will study in the environmental assessment. The locations shown can accommodate all of the toll operation scenarios under consideration: single point tolling or segmented tolling between I-5 and I-405.