60 Automotive Ergonomics: Driver–Vehicle Interaction
instead focus on looking centrally ahead (Harbluk et al., 2007). Even though time
looking outside of the vehicle remained unchanged, these results suggested a change
in drivers’ allocation of attention.
Whilst the presence of such a secondary task can increase the potential risk of
an accident or incident, it has been suggested that drivers may have up to 50% spare
visual capacity (Hughes and Cole, 1986) during ‘normal’ driving, suggesting that
some secondary tasks may be able to be conducted with no subsequent increase in
crash risk. Therefore, it is thought that other contributing factors also have to occur at
the same time for the risk to manifest itself (Angell et al., 2006). Contributing ...