This paper presents some first results of an investigation of the behavioural validity of the VTI Driving Simulator. Subjects' driving speed and lateral position were measured continuously during driving on a real road section and on a simulation of that same road section. The two factors, driving condition (simulator vs. road) and training, accounted for only a small proportion of the variance in driving speed, whereas mean driving speed differed considerably between subjects. Also, the mean lateral position differed between subjects, but the distance to the centreline was generally smaller in the driving simulator than on the real road section. A comparison of the variation in driving speed and lateral position along the road section indicated a highly consistent driving pattern within each of the driving conditions, whereas less consistency was found between the conditions. In particular the variation in subjects' lateral position along the road differed between the real and the simulated road section. This finding suggested that both absolute and relative measures of lateral position in the driving simulator differed from the same measures during driving on the real road. This result may be due to the fact that subjects' lateral position during driving on the real road was sensitive to the presence of other road users. Subjects' curve negotiation performance is another source of variance, which may account for some of the difference in lateral variation between the driving conditions. (Author/publisher)
Abstract