Device and method for detecting traffic jams

The invention relates to a device and a method for detecting traffic jams. Said device comprises an evaluating device (4) having a first, second and third interface (6, 8, 10), to which a GPS receiver (14), a speed measuring device (22) or a GSM transmitter/receiver unit (26) can be connected. Said evaluating device (4) comprises a memory unit (30) which stores the positional data, a calculating unit (32) which determines the direction of travel on the basis of the positional data, a comparative unit (34) for comparing the measured speed with a given speed limit, a time measuring device (36) for measuring the time during which the measured speed is below the speed limit, and a connecting unit (38) which is designed in such a way that, if the measured time exceeds a time limit, the current position and the direction of travel of the vehicle (2) are transmitted to the GSM transmitter/receiver unit (26) via the third interface (10) for transmission to a central control office (74). The inventive device and method have the advantage of enabling a traffic jam to be detected immediately.