Peripheral detection as a measure of driver distraction. A study of memory-based versus system-based navigation in a built-up area
- Published: Transportation Research Part F: Traffic Psychology and Behaviour, 6(1), 2003
- Authors: Harms, L., & Patten, C.
- Date Added: 28 Mar 2015
- Last Update: 28 Mar 2015
The study summarises previous results of secondary-task studies in traffic contexts and investigates the suitability of one secondary-task method, the peripheral detection task (PDT)-method, as a standard procedure for safety testing and evaluation of IVIS. The study was concerned with the effect of navigation messages on PDT-performance (reaction time and hit rate) taking into account also behavioural variables.
Professional drivers served as subjects. They had extensive prior local-knowledge and experience of driving in the built-up area in which the experiment took place. They were required to drive two different routes, one after memory and the other in accordance with navigation messages a standard navigation system installed in the car. In the navigation system condition subjects were subdivided into three groups, receiving either verbal, visual or both visual and verbal (full) navigation messages.
Twenty-four male, professional drivers were paid for their participation in the experiment. Eighteen subjects were taxi-drivers in the local area (Linköping) and the other six were professional drivers in the same area. All subjects were highly skilled drivers, familiar with having IT-components in their vehicles and familiar with driving in the built-up area in which they were required to drive. Their reported total annual mileage was 10,000–120,000 km with a mean of 60,000 km. The subjects were aged 30–60 years, fourteen subjects were between 40 and 50, six were younger than 40 and four were older than 50.
Driving behaviour was virtually uninfluenced by navigation condition (memory versus navigation system) and message modality (full, visual or verbal) whereas PDT-performance, showed some effects of navigation condition on subjects’ reaction times and hit rates.
Pairwise comparison of message modality within each three groups showed a prolongation in reaction time and a marginally significant decrease in hit rate with full navigation messages (combined visual and verbal ones).
Visual navigation messages affected only hit rate and no significant differences between navigation conditions were observed for the group presented with verbal messages.
The pattern of results suggests that the PDT-method is biased toward visual sources of information from IVIS.
As visual information processing is an important component in safe driving, the PDT-method is suitable as a predominant method in a test battery, but for unbiased measurement of distraction, methods less dependent on mode of presentation would be more appropriate.