The impact of intersection design on the driving performance of adults in the recovery phase of a turn

Driving, an instrumental activity of daily living, requires safe person-environment interactions. The effectiveness (safety) of four United States Federal Highway Administration intersection design guidelines in the recovery phase of a turn was tested on older and younger adults. Using kinematics measures from an instrumented vehicle, drivers negotiating improved and unimproved intersections were examined in Gainesville, Florida. The findings from a 2 x 2 repeated measures ANOVA (within-subject variable = intersection condition: improved versus unimproved; between-subject variable = age: young versus old) yield support for three manoeuvres: extended receiving lane, right-turn channelisation with acceleration lane and left-turn offset, but not for no acute turn angle. One interaction effect (age x intersection) existed and age effects (favouring older drivers) appeared for three manoeuvres, yet showed little practical significance, suggesting that these design guidelines benefit older and younger drivers alike. This study informs occupational therapists that enhancements in the environment have an impact on safer driving, particularly at urban intersections. A replication of the concept of this study, that is, testing intersection design guidelines in the United Kingdom, may generate valuable information on the plausibility of environmental design guidelines and their effects on the driving performance of older and younger adults.