Much of the buzz surrounding radio frequency identification (RFID) concerns supply chain management. However, another facet of RFID -- electronic toll collection -- has been in large-scale use for more than a decade. Now it's evolving into the next generation of systems proliferating in both usual and unexpected places.

Have a toll road nearby? Chances are there's an RFID transponder in your vehicle that allows you to pay the toll automatically when passing through the toll plazas at high speed.

Public-sector agencies operating toll roads use this tag technology to lower capital and operating costs, and reduce road congestion caused by cash payers. State and local governments from California to the Northeastern United States already have, or are beginning to implement, RFID-based toll collection systems.

In May 2004, the Harris County Toll Road Authority (HCTRA) in Houston, Texas, opened a new road -- the Westpark Tollway -- that relies exclusively on electronic toll collection, freeing it from the administrative burden of cash and coin collection. It's the first cashless toll road in the United States.

The HCTRA operates nearly 100 miles of toll roads, processing nearly 1 million transactions per day -- 65 percent of which are electronic.

Electronic toll collection on this scale requires a high-availability transaction processing system. Here, data processing starts on the road itself.

Electronic Transaction Consultants (ETC), a provider of lane and back-office systems for the HCTRA's toll operations, implemented the technically complex solutions that provide the multilane, highway-speed, nonstop toll collection required by the Westpark Tollway.

Sometimes referred to as "open road tolling," this collection method benefits drivers because there's no need to stop and pay tolls. It is also the most cost-effective collection method for the toll authority because no toll collectors or cash machines are necessary.

"Open road tolling is the norm for many toll roads in the planning stages today," said Tim Gallagher, founder and managing director of ETC. "RFID technology makes it possible to meet the challenges -- and gain the benefits -- of providing reliable toll collection capabilities in these dynamic, high-speed traffic conditions."

Getting the Data

Data is acquired when the automatic vehicle identification (AVI) system reads the transponder.

When a vehicle enters the lane, the entry loop sensor activates the AVI system. The transponder is read as it travels beneath the AVI antenna before the vehicle exits the entry loop. As the car continues through the toll gables, the tag reader checks with a local database to see if the account is valid.

If so, the transaction data is cached and sent to the back office, and the transaction processing begins. If not, drivers can expect a bill with their car's picture on it.

To prevent such violations, sophisticated cameras capture license plate images of more than 30,000 tagless violators per day in Houston. When the system doesn't recognize someone passing though the toll booth as a current account holder, the vehicle activates the cameras as the automobile crosses the enforcement system trigger loop. Once the picture of the car's license plate goes through an optical character recognition process, it is matched against a Texas Department of Motor Vehicles database that gives the operating authority the vehicle owner's name and address. Before using this information to send a bill, many organizations add a penalty amount, which helps recoup the cost of extra work while also dissuading the owner from repeating this deed in the future.

This is essentially a pay-by-the-plate method of billing, and depending on an entity's outlook, can allow customers without RFID-based tags to pay for tolls or other items. Some international operators -- including those running Toronto's largest toll road, Highway 407 -- use this method, realizing that not all traffic on their roads is local and out-of-province users may

Fred Philipson  |  Contributing Writer