Developing and evaluating static assessment rig criteria for the functional assessment of driving

Due to the increasing number of older drivers in most Western countries, reliable and valid functional assessment of fitness to drive is becoming ever more important. Research to define appropriate thresholds for tests on a static assessment rig (SAR) is described here. These rigs are used at assessment centre across the UK and elsewhere to help provide measurements of driving characteristics. Up to now, criteria for decisions on functional fitness to drive have not been explicitly established. To address this issue, a three phase research program was developed. The first phase obtained data from the driving population (non-disabled) for each of the SAR tests. To further expand the data source, in the second phase disabled drivers were tested on the SAR using their normal driving adaptations (if any), such as steering or braking adaptations. Following these two studies and an extensive literature review, criteria for the SAR tests were formalised and then validated by means of an experimental trial. Of the eight individual SAR tests, most of the proposed criteria performed well when compared against the outcomes of other assessment processes. From this, conclusions are presented regarding the use of the SAR as part of the overall assessment process, and for future research in this area.