PBS&J collected data from three large toll agencies regarding collisions at their plazas -- Florida's Turnpike Enterprise, the Orlando/Orange County Expressway Authority, and the Texas Turnpike Authority. The data show that conversion to open-roll tolling reduces crashes by more than 60 percent.

At traditional toll plazas, vehicles must slow down and pay tolls with either cash or an electronic transponder. At open-road toll plazas, only transponders are accepted for payment. Toll booths are removed and cars zoom through the plaza at highway travel speeds without needing to slow down or stop. All three agencies examined have converted some tollbooths to open-road tolling in recent years.

Some agencies such as the Texas Turnpike Authority offer both options. Cars with transponders can zip through the open lanes while drivers paying cash must pull into a traditional booth. In 2007 and 2008, TTA reported 96 collisions at its traditional booths but zero in the open-road tolling lanes.

"Most of the accidents at toll plazas involve vehicles colliding with some part of the toll plaza infrastructure -- guardrails, bollards, attenuators, barriers, or light posts," said Michael Davis, PBS&J's national tolls senior group manager. "ORT lanes are 'open' for good reason. There are no such obstructions for vehicles to hit."

Other crashes at tollbooths are caused by vehicles rear-ending the slowed or stopped vehicle in front of them. Such incidents are also dramatically reduced in open-road tolling lanes, the study found, since there's no need for vehicles to slow down and cause such traffic irregularities.