Designing the charging protocol for `Rekening Rijden´

Rekening Rijden is a road charging system aimed at a reduction of traffic flow. The charging protocol defines the interchange of messages forming a passage charging transaction. The paper describes the protocol at its present stage of development and discusses some of the challenges that were to be met. Points of interest are: the solution of timing problems within the constraints imposed by smart cards; the division of the transaction area into zones; and a protocol for multilane situations