The invention relates to a method for acquiring traffic situation data in
a network of traffic routes which is covered by a cellular mobile radio
network comprising a multiplicity of base stations and in which a
multiplicity of vehicles is moving which are in each case provided with
an operating mobile terminal for the mobile radio network. In this
method, characteristic patterns of values (called signal transit times in
the text which follows), which are representative of the signal transit
times with respect to the respective base station during the movement of
a terminal along the course of the respective traffic route, are
determined and permanently stored at least for some of the individual
traffic routes of the network of traffic routes at least for selected
base stations, the respective characteristic pattern or a sequence of
values representative of this pattern is mapped onto the course of the
respective traffic route (calibration). To obtain current traffic
situation information, the signal transit times of selected terminals
which are located within the transmission area of the respective base
station are detected and compared with the stored patterns.