Assisting the older driver - SWOV

Intersection design and the older driver
deviations from the common intersection layout (experience and schemata).
However, there was not enough information available to define these
hypotheses in more detail. For example, expecting that larger deviations
from the common intersection design lead to higher task demands is one
thing, but defining what the common intersection design is, is another.
Therefore, it was decided to change the character of the study from an
experimental study aimed at testing the abovementioned hypotheses to an
exploratory study aimed at gathering information about intersections at
which relatively many crashes occur in which older drivers are involved, and
comparing the characteristics of these intersections with those of
intersections at which relatively few crashes occur in which older drivers are
involved.
While carrying out this exploratory study, apart from the task demands of
passing a particular intersection and the capabilities of the driver, a third
factor was taken into account that may influence the involvement of older
drivers in crashes at a particular intersection: the older driver’s exposure.
Older drivers may pass certain intersections more often than others. This
may be the result of facilities they do and do not use (e.g., library, hospital,
school), but it may also be the result of consciously avoiding certain
intersections. The latter may be connected with the perceived difficulty of
passing them. One way or the other, exposure should also be taken into
account when comparing intersections with different shares of crashes
involving older drivers.
5.2.2. Method
Selection of intersections
Thirty intersections were selected using the road accident database of the
Dutch Ministry of Transport, Public Works and Water Management: 15
intersections at which relatively many crashes involving older adult drivers
occurred (Group Intold; at least 30% of all crashes at that intersection) and 15
intersections at which no crashes involving older adults occurred (Group
Intyoung). For practical reasons, all intersections were located in the Dutch
province of South Holland.
The intersections were selected based on the number of injury crashes that
occurred on them in the period between 1990 and 2000, the latter year being
the most recent year for which crash data were available at the time of
selection (2001). To make sure that the assignment of an intersection to one of
the two groups was based on solid data, at least 10 crashes had to have taken
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