The Pont au Double derives its name from the toll amount which was charged, a "double" denier, money used to pay for the construction of the bridge.

If the transponder fails to read, the license plate number is matched to the transponder account, and the regular toll amount is deducted from the account rather than a violation being generated.

The toll amount is electronically deducted from a pre-paid customer's account or recorded for a monthly billing statement.

Upon passing in a non-stop lane at a toll, a DSRC tag attached to the vehicle's windshield transmits its identifier and the toll amount is debited directly from the client's bank account.

The alliance supports a multipronged approach, she said, a cornerstone of which is "congestion relief pricing" - charging vehicles different toll amounts, more in prime time, less in off-peak hours.

Gantries constructed over each carriageway record registration plates and detect the e-TAGs, and deduct toll amounts automatically from the account linked electronically to each tag.

Ha'penny Bridge: This cast iron pedestrian bridge was built in 1816 over the River Liffey in Dublin and takes its name from the historical toll amount (a half-penny).

Vehicles on blacklist or vehicles without tag or with another vehicle's tag are charged with fine as high as the eleven times of toll amount.

Incentive pricing - setting different toll amounts for different times of day to try to flatten out peaks in the rush hour - has already become a reality because of E-Z Pass.

If a vehicle registered with I-Pass passes through a toll collection without the transponder, the toll amount will be automatically deducted from the respective I-Pass account.