A survey of over 1600 drivers is reported, the results of which are co
nsistent with those reported in an earlier study (Reason et al. 1990),
which identified a three-fold typology of aberrant driving behaviours
. The first type, lapses, are absent-minded behaviours with consequenc
es mainly for the perpetrator, posing no threat to other road users. T
he second type, errors, are typically misjudgements and failures of ob
servation that may be hazardous to others. The third type, violations,
involve deliberate contraventions of safe driving practice. In the pr
esent study the survey instrument used, the Driver Behaviour Questionn
aire, was also shown to be reliable over time. Each type of behaviour
was found to have different demographic correlates. Most importantly,
accident liability was predicted by self-reported tendency to commit v
iolations, but not by tendency to make errors or to have lapses. The i
mplications for road safety are discussed.