The road user is recognized as the key factor in accident prevention and advanced traffic management. The challenge for psychology is to provide the theoretical and empirical basis for understanding and modifying road user behaviour in the context of the social, legal, infrastructural and technological environment. The work identifies new developments in traffic psychology. It is divided into five topic areas: driver simulation and modelling; task performance (perception, workload, impairment, factors); social psychological approaches (attitudes, risk perception and acceptance, life-styles and personality factors); influencing road user behaviour (training, information, enforcement); and psychological aspects of systems design (transport telematics, ergonomics, road design).