Electronic Toll Collection (ETC), an adaptation of military "identification friend or foe" technology, aims to eliminate the delay on toll roads by collecting tolls electronically. It is thus a technological implementation of a road pricing concept. It determines whether the cars passing are enrolled in the program, alerts enforcers for those that are not, and electronically debits the accounts of registered car owners without requiring them to stop. The major advantage of ETC is that users are able to drive through the toll plaza at highway speeds without having to slow down to pay the toll. In some installations, ETC may also reduce congestion at the plazas by allowing more vehicles per hour/per lane.