Assisting the older driver - SWOV

Effects of a driver support system on workload and driving performance
situations, functionally young and middle‐aged participants did not very
much like this type of message. Afterwards, they were much more positive
about it, whereas the functionally old participants had become less positive
about it. However, the experience of receiving this type of messages was not
the only plausible explanation for the interaction effect. Unfortunately, the
questions about the appreciation of this type of messages differed between
the questionnaire administered beforehand and the one that was
administered afterwards. Both questions were preceded by an example of a
deviating road situation. Initially, the deviating road situation that was
described was about a crossing cycle path on which cyclists could arrive
from left as well as from right. However, while programming the experiment
it turned out that it was not possible yet to include cyclists as traffic
participants in the simulator environment. Therefore, other deviating rules or
situations had to be included in the questionnaire that was to be
administered afterwards: deviating rules or situations the participants had
actually experienced. The rules and situations which were described in the
second questionnaire related to changed speed limits and one‐way streets.
Since messages regarding changed speed limits were only provided if the
speed limit had risen from 50 to 70 km/h and participants had not already
altered their speed accordingly, functionally younger participants might
have been more interested in knowing they were allowed to drive faster than
functionally old drivers were.
Other studies that evaluated attitudes towards support systems showed that
younger drivers were less positive about messages regarding speed limits
than older drivers. For example, Viborg (1999) found that one of the
hypothetical support systems that were more often rated as useful by older
as compared to younger drivers, was an automatic speed adjustment system
(adjustment to the speed limit or to slippery and foggy conditions).
However, this system seems to be restrictive, whereas our system stimulated
drivers to increase speed in order to keep up with the traffic flow. One of the
systems our functionally older participants were positive about, the one that
would give advice on safe gaps to join or cross a traffic stream, was also
rated positively by Viborg’s older drivers. They were positive about a system
that warns the driver by a signal if it is unsafe to cross an intersection, and
about a system that warns the driver if it is unsafe to turn left at an
intersection. Similar results were found by Oxley & Mitchell (1995). They
tested the safety effects of and attitudes towards a system that provided the
driver with a colour light indication of whether the next gap in the stream of
traffic was long enough to allow a safe turning manoeuvre to be made. All
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