Can Driving Simulation Be Used to Predict Changes in Real-world Crash Risk?

This report considers and answers the question of whether driving simulation can be used to reliably predict changes in real-world crash risk. Following a review of the main issues relating to simulator validity and fidelity, including advantages and disadvantages of using driving simulators compared to test-track, or on-road, instrumented vehicle research, descriptions of a number of popular simulated dependent measures are presented. These measures are discussed in terms of their validity as the potential bases for conclusions regarding real world crash risk estimations. Some of the more common psychological and/or behavioural concepts targeted by simulated driving research are then defined and discussed, also in terms of their suitability for use in predicting actual on-road driver behaviour. Finally, it is concluded that, as long as policy makers and road safety administrators are aware of the limitations of simulator research, especially its inability to allow for the calculation of precise predictions of actual numbers of collisions, driving simulation offers a safe, relatively low cost, alternative to on-road instrumented vehicle or naturalistic research. The use of simulation is particularly recommended as a first step in the evaluation of novel road safety interventions.