Transit ridership increased by 38 percent on SR 520 after deployment of pricing and electronic tolling.
The Seattle/Lake Washington Corridor Urban Partnership Agreement projects evaluated tolling, technology, transit, and travel demand management strategies to reduce congestion.
Made Public Date

Seattle/Lake Washington Corridor Urban Partnership Agreement: National Evaluation Report

Summary Information

In 2006, the U.S. DOT initiated the UPA (Urban Partnership Agreement) program to demonstrate congestion reduction through strategies consisting of combinations of the 4Ts: Tolling, Transit, Telecommuting/TDM, and Technology. The Seattle/LWC UPA projects focused on reducing traffic congestion on SR 520 between I-405 and I-5, a heavily-traveled, east-west commuter route across Lake Washington. The lake separates Seattle from the eastern suburbs (including Bellevue and Redmond). These strategies included tolling all lanes of the SR 520 bridge, adding bus service in the SR 520 corridor, implementing active traffic management systems, and real-time traveler information signs on highways and at transit stops and stations. The suite of projects had a combined benefit-to-cost ratio of 1.76 due to travel time savings and reduced emissions.

Transit enhancements included 44 new buses and 90 additional one-way peak period trips across the SR 520 bridge; improvements to transit stops and park-and-ride lots; and new travel time signs.


Overall, ridership across the bridge increased 38 percent. Ridership increased 17 percent after UPA-funded transit service was added (Summer 2010 to Summer 2011), and increased another 18 percent after tolling (Summer 2011 to Summer 2012). Yet, service only increased by 26 percent.

Comparatively, ridership increased by 23 percent across the I-90 Bridge and by 8 percent on the overall King County Metro bus service.
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