Effects of time pressure on left-turn decisions of elderly drivers in a fixed-base driving simulator

In countries with right lane traffic left-turn manoeuvres at intersections are known to be particularly critical for elderly drivers. It has been suggested that the implementation and use of Advanced Driver Assistance Systems (ADAS) might offer a solution to compensate for age-related weaknesses in driving-related skills. In the present paper an experiment is reported which explored the effects of time pressure on the performance of left-turn manoeuvres supported by an ADAS function (‘time gap assistant’). The study was performed in a fixed-base driving simulator with 20 younger (22–37) and 21 elderly drivers (60–84) who were observed when negotiating left-turn manoeuvres on rural roads with and without the assistance function active. Subjects performed the task once under conditions of time pressure once without. Results indicate that both age groups used the assistance function to perform the left-turn manoeuvres with shorter time gaps. Under conditions of time pressure this effect was more pronounced, and the effects of time pressure were stronger for the elderly. However, there were only weak indications for a specific benefit of the assistance function for the elderly.

Research highlights
► The results presented here show success in the creation of a situation in a driving simulator where subjects experienced time pressure and adapted their behaviour accordingly.
► Time pressure was created in a way which cannot easily be controlled by the elderly by slowing or serialisation.
► Our results confirm the expectation that under conditions of time pressure subjects use the simulated ADAS function to perform left-turn manoeuvres with shorter time gaps but still safely. However, there were only weak indications for a specific benefit for the elderly.