Assisting the older driver - SWOV

Intersection design and the older driver
relatively few older drivers, one intersection is located in a neighbourhood in
which only 10% of the people is aged 65 or above (in 1999). The other two
intersections are located in a neighbourhood in which either 37% or 43% of
the people is aged 65 or above, the latter actually being the highest
percentage of older people living in the neighbourhood of the included
intersections.
5.2.4. Discussion
It was expected that the crash risk of older drivers would increase with the
complexity of the traffic situation, provided that drivers have to make
decisions with regard to road users that are about to cross their path, and
provided that drivers cannot use their experience to make these decisions.
These expectations were only confirmed for one of the intersection
characteristics which were expected to determine whether drivers have to
make decisions with regard to other road users: implementation of right of
way. Traffic lights were expected to reduce the number of decisions to a
minimum, whereas yield‐controlled intersections were expected to increase
the number of decisions to make. It turned out that at intersections at which
no crashes occurred in which older drivers were involved (Intyoung), traffic
was more often regulated by means of traffic lights than it was at
intersections at which relatively many crashes occurred in which older
drivers were involved (Intold). At the latter intersections, traffic was more
often regulated by means of yield signs.
Intersection characteristics that conflict with experience were hardly found at
any of the selected intersections. This could indicate that (older) drivers
could always use their experience and select the proper mental schema
without being misled by the intersection layout. If this was the case, the
automatically selected schema will then have directed the selection of
necessary information (see Section 4.4.2), and will therefore have reduced the
influence that complexity of the traffic situation has on task difficulty and on
the crash risk of older drivers. As a result, for the selected intersections, the
amount of traffic‐related information that was visible while approaching an
intersection, the quality of the information, and the time pressure that was
imposed on the driver would have been less relevant for the prediction of the
number of crashes in which older drivers were involved.
Nevertheless, it is interesting to note that according to the characteristics that
were expected to determine the amount of traffic‐related information, the
quality of traffic‐related information, and the time pressure that is imposed
87