Improving the detection of vulnerable users by motorists

Science topics April 2015 Road safetyHuman behaviour

Joceline ROGÉ, Researcher in cognitive psychology - TS2 Department, LESCOT Laboratory

      Vulnerable road users account for half the world’s road fatalities: 23% are motorcyclists, 22% are pedestrians and 5% are cyclists (World Health Organization, 2013). In France, the number of fatalities for each category of vulnerable user are similar to these figures: 24% are powered two- or three-wheelers, 12% are pedestrians and 4% are cyclists (data from 2010). These users therefore represent a major concern for road safety. Studies from a number of countries lead to the conclusion that senior drivers are more involved in collisions with vulnerable road users.


Improving the detection of vulnerable users by motorists - Ifsttar - The visual attentional capacities of a pedestrian - Ifsttar

Visual attentional capacities partly to blame

      The fact that senior drivers detect vulnerable road users late could it be explained by a malfunction in their information processing sequence. A vulnerable road user first appears in the person’s peripheral visual field and a saccade of the eye is necessary to identify them. Perhaps, therefore, the ability to identify a vulnerable road user depends at least partly on the attentional capacity of motorists when they must perceive information in their peripheral visual field. One way of assessing this is to evaluate the size of an individual’susual field of view during driving. This is the surface area around the fixation point in which a person is able to process information while performing a dual task involving the central and peripheral parts of their visual field. During simulated car driving, it is possible to measure this field. Investigation has shown that its size is not constant and it can vary on the basis of the characteristics of the driving task and between individuals. For example, as drivers age the usual field of view deteriorates and a form of tunnel vision develops when driving (Rogé, 2009).


The technique for improving visual attentional capacities on a driving simulator

      A training method which improves drivers’ usual field of view could have a positive effect on the detection of vulnerable road users in the road environment.

     Specific training conducted on a driving simulator led to a considerable improvement in the usual field of view for a group of elderly drivers (with an average age of 70 years). Both before and after the training process, the capacity of the seniors in question to detect vulnerable road users (pedestrians and powered two-wheelers) was measured during a simulated driving task (image on the left). The proposed training was beneficial as it enabled the subjects to detect pedestrians in the road environment more easily (image on the right). The visibility distance for pedestrians (children, adults or immobile or moving elderly persons) was substantially better after training.



The LEPSIS driving simulator (on the left) and an example of pedestrian to be detected during simulated driving (on the right).

The outlook for future research using this training technique

      Other experiments need to be conducted to improve our understanding of the effects of training on the visual attentional capacities of drivers. We need to determine the optimum duration of training in order to obtain the maximum improvement in the visibility of vulnerable road users. It would also be interesting to see how long the improvement of theusual field of view remains after the end of training. Finally, we need to test whether the improvement in the pedestrian visibility distance also occurs in a natural environment.




Find out more ...

  • Rogé J., Ndiaye D. and Vienne F. (2014) Useful visual field training: a way to improve elderly car drivers’ ability to detect vulnerable road users, Transportation Research part F: Traffic Psychology and Behaviour, 26, 246-257. Accessible via ScienceDirect
  • Rogé, J. Pébayle, T. (2009) Deterioration of the useful visual field with ageing during simulated driving in traffic and its possible consequences for road safety, Safety Science, 47, 1271-1276. Accessible via ScienceDirect
  • World Health Organization, 2013. Global status report on road safety 2013, supporting a decade of action, WHO, Department of violence and injury prevention and disability, Geneva, Switzerland, p. 318.