ESTIMATES OF DRIVING ABILITIES AND SKILLS IN DIFFERENT CONDITIONS

Objectives. This research was a preliminary effort to determine whethe r various driving situations seemed to require different driving skill s and abilities and to identify the relative demands of specific physi cal, perceptual, cognitive, behavioral, and operational skills and abi lities in different driving situations. Method. Experienced driver eva luators and trainers estimated the magnitude of driving abilities and skills for different photographed driving situations. Pictures of driv ing scenarios were counterbalanced for road type, traffic condition, a nd weather condition. Results. A multifactorial analysis of variance o f the total score for each scenario revealed significant main effects for road type and traffic condition but not for weather condition. Hig hway and city driving were rated as significantly more demanding overa ll than residential driving, but no difference was found between city and highway driving. Estimates of the overall demands for driving in h eavy traffic were significantly greater than in light traffic. However , driving in inclement weather was not regarded as significantly more demanding than driving in sunny weather. Addditionally, significant in teraction effects were found for road type by weather condition and tr affic by weather condition but not for road type by traffic condition. Through multivariate methods to evaluate the significance of individu al abilities and skills across conditions, significant main and intera ctive effects were found for road type, traffic condition, and weather condition. Post hoc analyses showed the impact of these effects on su ch abilities and skills as scanning, attention and concentration, info rmation-processing speed, and others. Conclusion. Evaluators' quantifi ed estimates of driving demands showed driving as a complex task that (a) requires high levels of abilities and skills in all situations; (b ) demands greater abilities in some situations than in others; and (c) involves different kinds and various degrees of abilities and skills, depending on the demand characteristics of the situation.