Assisting the older driver - SWOV

Effects of a driver support system on workload and driving performance
would give. However, after having experienced these messages functionally
old participants became less positive about them, whereas the younger age
groups became more positive. Paired samples‐tests showed that these effects
of experience on user acceptance were only significant for the functionally
middle‐aged (usefulness: t(19) = 2.917, p = 0.009; satisfaction: t(19) = 3.729, p =
0.001).
Opinions about the two other types of messages (‘safe gaps’ and ‘view of the
intersection’) were not affected by experience. Opinions regarding their
usefulness and their satisfying character remained the same, both in general
and when taking the functional age of the participants into account.
8.4.3. Effect of driver characteristics
To find out more about the participants that were positive about the system,
independent samples‐tests were carried out using background variables such
as number of disorders, number of situations that people avoid, number of
manoeuvres they have difficulties with, number of manoeuvres for which
they would like driver support, and daily use of technical devices (e.g., cash
machine, teletext, mobile phone, internet). For each background variable, two
groups were made that were compared on their opinions about a
hypothetical system and on their opinions after they had experienced the
system. To adjust for the fact that per time of measurement and group
comparison 8 tests were carried out (two for each type of message:
usefulness and satisfaction), a Bonferroni correction was used (0.05/8 =
0.00625; 0.01/8 = 0.00125; 0.001/8 = 0.000125). Significant differences were
found in the opinions about the hypothetical system between participants
not having any disorders and those who had one or more, between
participants not having difficulties with any manoeuvres or only with one
manoeuvre and those having difficulties with two or more manoeuvres, and
between participants not needing any help or only wanted assistance with
one manoeuvre and those who wanted assistance with two or more
manoeuvres (see Table 8.17; asterisks indicate significant differences between
groups of participants). As expected, participants who had more disorders,
or who had difficulties with more manoeuvres or who would like to have
assistance with several manoeuvres were more positive about the
hypothetical assistance systems than participants without any disorders,
difficulties or desire for assistance. No differences were found in opinions
after participants had experienced the system(s).
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