Abstract
By means of unobtrusive observation of road user behaviour based on video an objective quantification of behavioural aspects like speed, speed changes, path chosen, place of stopping, etc. is carried out. For describing the danger involved in an interaction between road users the time-to-collision (TTC) is used. After a short description of the method itself some applications are discussed, which illustrate that the method not only enables an objective registration of traffic conflicts, but also gives good possibilities for further analysis of the underlying behaviour of road users.