Client:
Washington State Department of Transportation (WSDOT)
Duration:
2010 to present (15+ years)
Solutions:
Multi-Lane Free Flow, Open Road Tolling with All-Electronic Toll Collection (AET)
Challenges
Tolling a Historic Bridge Without Harming the Habitat It Crosses
The Evergreen Point Floating Bridge is one of only two ways to cross Lake Washington, carrying 115,000 vehicles a day between Seattle and the region's fastest-growing employment centers. Skipping it means a 90-minute detour on surface highways. By the time Washington's Legislature authorized tolling the bridge in 2008, both to help fund its replacement and to manage the congestion, the span was already more than four decades old and due for significant maintenance.
- A temporary system with permanent-grade reliability: Tolling on the original bridge would only run until its replacement opened, but WSDOT still required the same revenue assurance and uptime as a long-term system, at a cost that matched its shorter lifespan.
- A floating structure: Constant movement and vibration on the bridge itself created equipment placement and calibration challenges no fixed-span project would face.
- A sensitive ecological zone: The bridge crosses habitat for Chinook and Cojo salmon, requiring construction and operation practices that would not disturb the surrounding waterway.
Project Scope
In April 2010, WSDOT selected Kapsch to design, install, and maintain a two-way, single-point congestion-priced toll system on the then-48-year-old SR 520 floating bridge, a first-of-its-kind tolling project. The system covers Multi-Lane Free Flow, Open Road Tolling with All-Electronic Toll Collection. The full scope covers:
- Automatic Vehicle Identification (AVI) and Video Image Capture: In-lane camera and lighting systems capture transponder reads and license plate images at the toll zone.
- Zone controller hardware and communications equipment: Engineered for accurate vehicle framing, image triggering, vehicle classification, and tag-to-vehicle assignment.
- GoodToGo! account integration: License plate images of vehicles without a transponder are matched to a GoodToGo! account and billed directly, with no toll booths on the bridge.
- Remote Operations and Maintenance System (ROMS): Tracks and reconciles every transaction and violation across the system.
- Host system integration: Connects toll host servers to WSDOT's Traffic Management Center and Customer Service Center, supporting Changeable Message Sign operations and customer service.
- Parallel-redundant equipment: Installed throughout to minimize downtime and protect revenue on a structure where equipment access is inherently harder than on a fixed span.
Solutions
A System Engineered for a Moving, Protected Structure
- End-to-End Automated Tolling: Every vehicle crossing the bridge is identified by transponder read or license plate image, matched to a GoodToGo! account, and billed automatically. There are no toll booths and no manual review required for a standard transaction.
- Complete Operational Visibility Through ROMS: The Remote Operations and Maintenance System gives WSDOT's operations, revenue management, and maintenance staff full audit and reconciliation across every transaction. Integrated video imaging, real-time sensor data, automated event alerts, and historic playback give staff complete situational awareness of the system at all times, critical on a structure where a technician can't simply walk out and inspect equipment during heavy traffic.
- Built for the Bridge It Sits On: Kapsch designed around the realities of a floating, ecologically sensitive structure rather than adapting a fixed-span design after the fact. Camera strobe intensity was selected specifically to avoid disturbing salmon in the surrounding habitat. Installation was planned to minimize interaction with lead-based paint and to contain asphalt debris. Parallel-redundant equipment was installed throughout to withstand the bridge's constant movement and vibration without losing accuracy or uptime. Commercial off-the-shelf hardware kept the system upgradable and cost-effective for a bridge with a defined, shorter operational lifespan.
Impact
$32 million in gross revenue in its first year of operation (2012)
Demonstrating the system's revenue-generating capacity from day one.
Independently audited accuracy greater than 99.97 percent
The system met or exceeded every one of WSDOT's performance requirements, including Vehicle Detection, Automatic Vehicle Identification (AVI), Automatic Vehicle Classification (AVC), Image Capture, and Digital Video Audit System (DVAS) operation.
The system that started a statewide program
SR 520's design and delivery experience led directly to Kapsch winning WSDOT's Statewide Tolling Integration contract in June 2012, expanding the same approach to the SR 520 replacement bridge, the SR 99 tunnel, and I-405.
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