Estimates of driving abilities and skills in different conditions.

OBJECTIVES This research was a preliminary effort to determine whether various driving situations seemed to require different driving skills and abilities and to identify the relative demands of specific physical, perceptual, cognitive, behavioral, and operational skills and abilities in different driving situations. METHOD Experienced driver evaluators and trainers estimated the magnitude of driving abilities and skills for different photographed driving situations. Pictures of driving scenarios were counterbalanced for road type, traffic condition, and weather condition. RESULTS A multifactorial analysis of variance of the total score for each scenario revealed significant main effects for road type and traffic condition but not for weather condition. Highway and city driving were rated as significantly more demanding overall than residential driving, but no difference was found between city and highway driving. Estimates of the overall demands for driving in heavy 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. Additionally, significant interaction effects were found for road type by weather condition and traffic by weather condition but not for road type by traffic condition. Through multivariate methods to evaluate the significance of individual abilities and skills across conditions, significant main and interactive effects were found for road type, traffic condition, and weather condition. Post hoc analyses showed the impact of these effects on such abilities and skills as scanning, attention and concentration, information-processing speed, and others. CONCLUSION Evaluators' quantified 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.