Defining criteria for the functional assessment of driving

Given the growing number of older drivers, accurate functional assessment of fitness to drive is becoming increasingly important. This paper describes work to define appropriate thresholds for cognitive, perceptual and physical tests on a static assessment rig (SAR). These rigs are used at Mobility Centres across the UK to provide measurements of driving characteristics as part of an assessment. However, criteria for decisions on functional fitness to drive have not been clearly defined or validated for SARs. A first study obtained normative data from the non-disabled driving population for each of the SAR tests. In the second study, disabled drivers were tested on the SAR; approximately half of these drivers used some type of steering, braking or accelerator adaptation. Following these two studies, criteria for the SAR tests were formalised and then validated by means of an experimental trial. Recommendations are made regarding the use of the SAR as part of the overall assessment process and for future research.