Comparing the driving performance of average and older drivers: The effect of surrogate in-vehicle information systems

This paper outlines the results of a study conducted as part of the EU funded FP5 project HASTE (Human Machine Interface And the Safety of Traffic in Europe). Two Surrogate In-Vehicle Information Systems (S-IVIS) were developed for this study: a visual S-IVIS was designed to investigate the effect of increasing visual information on driving performance, whilst the effect of increasing cognitive demand was studied using a non-visual auditory memory task. The interaction between each of these tasks and driving was then observed in a field study using Finnish drivers, and in the Leeds Advanced Driving Simulator, using British subjects. For each site, drivers were allocated to one of two age groups: (i) average drivers aged between 25 and 50, with at least five years’ driving experience and (ii) older participants over the age of 60 who drove an average of 10,000 miles per year. Each secondary task was performed in isolation, and in combination with driving. As shown in previous research, compared to the older drivers, average drivers were more successful at performing the two S-IVIS tasks, both in isolation, and with driving. In the field, the effect of the two S-IVIS tasks was found to be more profound on older drivers, resulting in closer car following, more speed variation and less lane keeping compared to average drivers. The effect of the two secondary tasks on simulated driving was found to be slightly different to that of the field drives, with older drivers keeping longer distance headways and reducing their speed in the presence of the S-IVIS tasks. The implications of these findings are discussed.