Abstract: The invention relates to collecting of traffic data with the aid of a mobile station network. Such areas are determined in the mobile station network, wherein the terminal equipment communicates with the network with the aid of one or more predetermined messages. Based on the message between the network and terminal equipment and relating to a first area a first time by the clock is stored, and based on the message between the network and the same terminal equipment and relating to a second area a second time by the clock is stored. The times by the clock are used in order to obtain traffic data by calculating, for example, the time spent on moving from one area to another. By determining the distance between areas along the road it is possible also to determine the speed of the vehicle. Information may also be collected to form a statistic distribution.