However, the way in which Montoro et al. constructed the questions
resulted in important details being obscured. For example,
the ‘‘no change’’ group consisted of drivers who frequently undertook
the risky behaviours both before and after the PPS, as well as
those who never undertook the risky behaviour, irrespective of the
PPS. Two measures of behaviour frequency (before and after) are
necessary in order to adequately evaluate the effect of the PPS.
Therefore, the main aim of the present study was to investigate
self-reported changes in risky driving behaviour, including: drink
driving, driving under the influence of drugs, speeding and using
a handheld mobile phone while driving. Furthermore, the study
also aimed to investigate changes in seat belt and helmet use. This
was attempted in a sample of young Spanish drivers two years
after the introduction of the PPS by comparing their self-reported
behaviour before and after the law. Furthermore, the research
investigated whether there were differences by: gender, whether
they had lost points from their licence and whether they had been
involved in a crash in the last 12 months.