This paper discusses problems of traffic safety in terms of modern cog
nitive psychology. Driving is described as a form of self-regulated be
haviour and it is discussed in terms of two levels of control: automat
ed behaviour, which is overlearned and where information is acted upon
as signals and deliberate behaviour which involves decision making an
d where information is treated as symbols. The decisions at the delibe
rate level set the conditions under which the automated behaviour has
to operate, and when these decisions create conditions that overtax th
e automated skills of the driver, accidents will happen. The decisions
at the deliberate level are analysed in terms of Fishbein and Ajzen's
theory of planned behaviour, and results are reviewed which indicate
that the drivers' social norms, rather than their expectations concern
ing accidents, is the most potent factor determining actual driver beh
aviour. It is also noted that driving may be less of a self-regulated
task for professional drivers than for the general driver, and that th
is may explain why consistent individual differences in accident rates
have mainly been found for the former category of drivers.