A barrier toll system
(also known as an open toll system
) is a method of collecting tolls on highways using toll barriers
at regularly-spaced intervals on the toll road's mainline. Motorists are typically charged a flat-rate toll, unlike toll roads with a ticket system
where the toll rate is determined by the distance traveled or number of exits passed. Some highways use coin-drop machines on toll plazas. For toll roads whose ramps have no tolls, it is possible to exit the toll road before the mainline toll plaza, use local streets to bypass it, then re-enter the highway via an interchange on the other side of the toll plaza. Thus it is possible to drive on some barrier toll roads paying less or not paying at all. Some roads disallow avoiding the barriers by removing highway entrances after and exits before toll plazas. One example of such highway planning is Dallas North Tollway
, which places toll plazas on exits before and entrances after mainline toll barriers. This system can create more congestion than the ticket system due to motorists having to pass several toll barriers each time they travel down the highway.