Behavioral And Workload Measures In Real And Simulated Driving: Do They Tell Us The Same Thing About The Validity Of Driving Simulation?

Only few studies have compared the level of mental workload induced by driving a real vehicle and driving a simulator, and they have found conflicting results. The goal of the present study was to examine whether driving behavior and mental workload level differed between driving a (low-cost) simulator and driving on roads. With this purpose, we developed the virtual equivalent of a route where participants could drive freely. In both driving conditions, we examined whether behavioral and mental workload measures differed or not. Results confirmed that driving speed in simulated condition closely matches that in real driving. Workload level, however, as measured by blink frequency, response time to a subsidiary task and subjective ratings, was consistently higher in the simulator. While behavioral validity of low-cost driving simulators is relatively robust for speed measures, no similar conclusion can be drawn regarding attentional resources allocated to vehicle handling. Some of the results supported the relative validity of driving simulators in terms of mental workload. The combined evaluation of behavioral and workload measures confirmed discrepancy between these two dimensions of driving simulators validity and suggests that the validity of driving simulators is also to be investigated at the level of the underlying processes for in-depth evaluation to better approach the real conditions of driving.