A transponder or smart card is placed in the windshield of the vehicle. A computer deducts the appropriate toll from that customer's prepaid account. Charges vary by time of day - less in off peak periods and more during congested periods. Payment is enforced by photographing the license plates of fare evaders. Other collection methods include toll booths and area licensing.
Toll booths use manual collection at entrances or exits.
Area licensing requires passes or windshield stickers that are purchased for use in a specified area. These other collection methods could be used as possible adjuncts depending on the specific needs of a pilot project.