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Ensure electronic toll collection systems are interoperable with neighboring toll facilities.

The Washington State Department of Transportation’s experience with planning for tolling implementation.

Date Posted

Washington State Comprehensive Tolling Study: Final Report – Volume 2: Background Paper #8: Toll Technology Considerations, Opportunities, and Risks

Summary Information

The comprehensive tolling study conducted by Cambridge Systematics for the Washington State Department of Transportation (WSDOT) set out to provide recommendations to guide Washington as it develops toll facilities in the State. These policies emerged from background research and technical analysis.

The Washington State tolling study describes different types of electronic toll collection (ETC) methods, how they are applied to various toll facilities, note lessons learned from past experiences, and identifies the advantages and disadvantages of each. Furthermore, the study addresses institutional issues relating back office operations and enforcement processes.

The deployment of electronic toll collection (ETC) is well established in North America and overseas. The E-ZPass Program, under the Interagency Group in the eastern part of the United States, involves over 20 separate toll agencies and 11 million transponders. The FasTrak Program in California has over 1.25 million transponders and is statewide. Out of these experiences, key lessons have been identified for achieving effective interoperability in tolling systems.

  • Ensure interoperability at the transponder level. Interoperability at the transponder level, allows a customer to use the same physical transponder on all of the interoperable facilities, but the customer may need to set up a separate account with each agency or facility. This approach is commonly used for electronic weigh station bypass programs, where trucks are equipped with the same transponder, but must register for the program that is used by a specific state. For example, the program in Washington State uses the same transponder for the program in California, but the trucker must be registered with both programs.
  • Provide easy user interface by consolidating operations as much as possible. Consolidating operations is the ultimate form of interoperability. It establishes a single customer service organization where there is one account, one system, and one point of contact. Because of the potential cost savings and the provision of consolidated customer service the single consolidated operations approach has evolved in many areas. A recent example is the consolidation of systems and customer service centers in the San Francisco Bay Area from two to one. Three key factors to consolidated operations include:
    • Requiring only one transponder in customer’s vehicles for electronic toll collection;
    • Providing a single customer service telephone number, available for all tolling customer inquiries; and
    • Issuing a consolidated statement to customers for all activity at all tolling facilities.
  • Allow for smooth flow of information by developing peer-to-peer exchanges. Peer-to-peer interoperability means that separate customer service centers are maintained by agencies that have agreed to exchange transactions and account files so that the customer has only one transponder and one account. However, for transaction and violation inquiries, customers may be required to deal with separate customer service centers, depending on the facility that they used. The E-ZPass Program, which extends from Maine to Virginia with over 20 separate toll agencies and 11 million transponders, is an excellent example of the successful implementation of a peer-to-peer exchange.
  • Plan for changes in tolling technologies, so that interoperability can easily be attained in the future. Tolling technologies are rapidly evolving making it essential for agencies to adhere to set standards in order to ensure future interoperability. An example of this can be found in the deployment of five different dedicated short range communications (DSRC) protocols for electronic toll collection in the United States which has had significant impact on interoperability. These deployments are generally geographically separated with limited need for interoperability initially. However, the lack of interoperability among these automatic vehicle identification (AVI) technologies has been recognized as a significant problem. Accordingly, U.S. Department of Transportation (DOT) has commissioned a consortium of the major transponder manufacturers to develop a national DSRC standard. The device is being built around a newly allocated radio frequency (5.9 GHz) and the specific requirements of DSRC for transportation applications. The new DSRC transponder should be available for testing in early 2006, with a deployment decision by the U.S. DOT and the automotive industry expected in 2008. The new transponders could be part of new vehicles shortly after 2010. This means that it will take until at least 20 years for transponder to be incorporated into all U.S. autos, since it takes approximately 15 years for the entire America car fleet to turn over. To bridge this gap between available and future technology, the Washington State DOT has:
    • Selected the e-Go™, battery-less, sticker transponders from a single vendor as the primary AVI technology for ETC in the State;
    • Installed dual DSRC protocol readers to allow the reading of the existing battery powered transponders installed on commercial vehicles participating in the WSDOT electronic weigh station bypass program, in addition to the e-Go™ tags; and,
    • Developed and implemented a plan for migrating to the new U.S. standard 5.9 GHz transponder so that multiple vendors can supply a standard toll transponder to the State in the future.

Achieving interoperability among ETC systems is paramount to the success of any tolling operation. In order for it to be truly effective, interoperability needs be attained both at the local and regional scale. Creating one customer service number, one transponder and one account for all users is a logical first step. Not only does this facilitate a smooth flow of information among neighboring agencies but it also creates simplified process for customers. Lastly, implementing agencies need to anticipate ongoing changes in tolling technologies and plan accordingly, and ensure that current systems will be interoperable with future upgrades. Achieving interoperability will improve the mobility and efficiency of the roadway networks, and increase customer satisfaction.