Austin American-Statesman | October 09, 2007
By Ben Wear

A glitch in the equipment on three Austin roads has caused about 50,000 double-billings since charges began in January, Texas Department of Transportation officials said Monday. The problem has occurred one of every 600 times a car passed one of the roads' tolling points.

Agency officials say that they have made a number of equipment and software changes in the past few weeks to virtually eliminate the problem — the frequency would now be more like one in every 2,000 toll transactions — and that every customer affected by the snafu now and in the future will have the charges credited.

"We will reverse all of them," said David Powell, the state Transportation Department's director of turnpike information technology and toll operations.

The problem, Powell said, had to do with antennae on the overhead gantries that communicate with electronic toll tags on car windshields.

Poor aiming of those antennae, Powell said, can lead to a number of scenarios resulting in double charges.

The antennae, which are actually flat panels, have to be pointed at a certain spot. If the panel is tilted incorrectly, it can read the tag on one car while believing that it is communicating with a car in a different spot. Then, those cars that have already seen debits to their tag accounts might be photographed by the equipment at a different spot and debited again.

Although a number of antennae were out of adjustment, Powell said, the main culprit was the one looking down on the westbound center lane at the Lake Creek toll plaza on Texas 45 North. Powell said the antennae, installed by United Toll Systems, could have been installed incorrectly or knocked askew during construction.