Forecasting toll revenues accurately
Revenue experts projected traffic and tolls through 2056, building accurate forecasts to enable bond sales and financing.
Practices
Replacing a vulnerable bridge with a toll financing solution
Seattle’s original SR 520 floating bridge—built in the 1960s—had become unsafe, outdated, and inaccessible for pedestrians and bicyclists. WSDOT partnered with CDM Smith to conduct a traffic & revenue study and construction of a new 1.44-mile bridge, the longest floating bridge in the world.
Coordinating across agencies
CDM Smith helped to resolve rate concerns with the state Transportation Commission, advisors, and fiscal consultants.
Delivering multimodal access
The state's new bridge now includes HOV lanes, transit facilities, and a bike-pedestrian path for safe multimodal travel
Ensuring long-term financial stability
CDM Smith is providing updated yearly forecasts based on bridge tolling data, changes in toll rates and construction schedules.
Bolstered by accurate forecasts and strong coordination, WSDOT's new bridge now provides three lanes each way, multimodal access, and resilience against natural hazards. One year after opening, the SR 520 floating bridge received the prestigious Grand Conceptor Award from the American Council of Engineering Companies, cementing its place as a model of modern infrastructure delivery.