Speed behaviour as a choice between observing and exceeding the speed limit

Despite speed behaviour being defined as a choice between several possible speeds, studies using theory of reasoned action or theory of planned behaviour to predict and understand speed behaviour have focused on exceeding and not on observing the speed limit. This study examines whether the evaluation of exceeding but also of observing the speed limit contributes to improving predictions of self-reported speed behaviour and determining intentions to produce each of these two behavioural options. For a specific driving situation (straight road with 90 km/h speed limit), 238 young male drivers reported the speed at which they would drive at and where asked to assess the theory of planned behaviour key constructs with respect to observing and exceeding the speed limit by at least 20 km/h. Results showed that the amount of explained variance of self-reported speed behaviour, as well as intentions to observe and to exceed the speed limit by at least 20 km/h, increased significantly when the evaluations of the two options were introduced in the same stepwise regression analysis. Theoretical and practical implications of the results are discussed.