AutoPASS

Autopass (stylized autoPASS) is an electronic toll collection system used in Norway. It allows collecting road tolls automatically from cars. It uses electronic radio transmitters and receivers operating at 5.8 GHz (MD5885) supplied by the Norwegian companies Q-Free and Fenrits.

The system involves the installation of a DSRC based radio transponder on the windscreen of a vehicle, and to sign an agreement with one of the toll collection companies in Norway. Tolls are charged at toll plazas as before, but cars can drive past in over 100 km/h. The system is administrated by the Norwegian Public Roads Administration. All public toll roads but one in Norway use the system, in addition to tests for use of the system on some car ferries. The primary reason that some projects don't support Autopass is that they charge both for the car and for passengers, which the system cannot support. All projects using Autopass can only charge per car. The only manual toll road left is the Atlantic Ocean Tunnel.

Each Autopass unit contains a microcontroller which will process requests from the road side, and respond with the proper information to the road side.

There are 5 generations of cryptographic key pairs inside each Autopass unit, which are unique for each unit. The cryptographic keys are used for authenticating the unit when passing a toll plaza, thus making it difficult to make fraudulent copies of an Autopass unit. Unlike similar DSRC based tolling systems used in many countries, there is no access control in the Norwegian system, the unique ID within the unit is available to be read for those who have the proper DSRC equipment.

There is an internal storage space for 100 log entries, which are normally updated each time a vehicle owner is charged when passing a toll plaza. This is a collection of receipt entries which includes the time, date and the station identity of the toll plaza which did the tolling transaction.

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Wikipedia