The amount of tax payable depends on what time of the day a motorist enters or exits the congestion tax area.

In summer, for example, motorists may enter the tunnel from the east where it is sunny and warm, and emerge on the west end into fog and cold.

If that happens, the system's computers have no way of knowing where the motorist entered, and cannot determine the proper toll when the driver exits.

They are also used on ramp metering, where motorists enter a freeway in heavy traffic.

It is one of only two ways that motorists can leave or enter the Florida Keys (the other is U.S. Route 1).

People in Washington Township chafed at the situation for years, in part because motorists entered and exited the toll plaza in their town.

A new generation of cashless tolling systems eliminates these problems and allows motorists to enter and leave tolled roads at full speed.

These solid lines are interrupted on crossings to allow motorists to enter or leave the road.

If a motorist did enter, he would eventually get a bill.

Collisions typically occur when a motorist is entering or leaving the circular intersection.