Assisting the older driver - SWOV

Intersection design and the older driver
to the distance between a roundabout and cyclist or pedestrian crossings.
Both design elements are related to the view of traffic. As regards the
connection of streets to a roundabout, Brouwer, Herland, and Van der Horst
(2000) state that right angle connections are more effective in reducing
driving speed, and provide a better view of the traffic on the roundabout for
drivers that are about to turn onto the roundabout, than do tangential
connections. To ensure that drivers who leave the roundabout have a good
view of cyclists and pedestrians that have right of way, the angle between the
driver and cyclist or pedestrian crossings at connecting streets should also be
90 degrees. This angle can only be obtained if the crossing is placed at
approximately one length of a car from the circulation area (i.e., the traffic
lane on the roundabout; Linderholm, 1996, cited in Brouwer, Herland & Van
der Horst, 2000; CROW, 1998b, 2002). More generally, it can be emphasized
that the traffic control devices and physical layout and appearance of
roundabouts need to be uniform from one installation to another (Lord,
Schalkwijk, Staplin & Chrysler, 2005). This gives (older) drivers the
opportunity to gain experience with roundabouts, and at the same time
develop mental schemata for managing roundabouts that help them safely
negotiate not only roundabouts that are situated in their own town, but also
those that are situated in another town (see e.g., Wouters, Slop, Lindeijer,
Kuiken & Roendersloot, 1995).
5.3.3. Traffic signs and road markings
As people age, visual functions decline as well as the ability to separate
important from unimportant information (selective attention) and the ability
to divide attention between, for instance, different aspects of the road scene
(Chapter 2). This probably makes it more difficult to detect traffic signs and
obstacles. Road design elements can anticipate these difficulties by providing
appropriate placement and legibility of traffic signs (e.g., street‐name signs),
conspicuousness of obstacles (e.g., kerbs, medians, and traffic islands), and
recognizable intersection control (who has right of way) and lane assignment
(Staplin et al., 2001).
Street name signing
The importance of the legibility of street name signs has to do with the time
and effort needed to read the name of the street. Factors which influence the
legibility of street‐name signs are among others, contrast, luminance, font,
letter height, letter width and interletter and interword spacing (Staplin et al.,
1998). These factors become more important as the eyesight of a road user
becomes worse. Older drivers, because of their age‐related deterioration of
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