Abstract
This report-gives the results of a research done by the TH in Delft in cooperation with SWOV and TNO. The research consists of 3 parts: 1. a Research into the measuring methods and the influence of the measuring on the traffic behaviour. 2. Research into the stability of traffic streams. 3. A research into the influence of speed limits on the traffic-behaviour in curves in 2-lane roads. 2 measuring methods have been developed; aerial photography and the measuring of vehicle-trajectories with time recorders. The exactitude of the measurements with radar and time recorders appeared to be sufficient. From the measuring of vehicle-trajectories appeared that traffic flow is not stable, from a statistical point of view.