Two experiments were performed in which drivers' cognitive load was measured by the time taken to complete calculation tasks presented to them while driving on prespecified routes. Experiment 1 was conducted on two different driving routes. Both routes included driving on a highway and driving through a village area. Mean driving speed was lower and mean calculation time was higher in the village areas than on the adjacent highway sections of the two driving routes. Across successive 100-m intervals of the two driving routes, drivers' cognitive load was found to be inversely related to their driving speed. Experiment 2 tested the same dual-task method on driving routes including two rural junctions. At both junctions driving speed decreased with decreasing distance to the give-way line and the drivers' cognitive load was highest while approaching and driving through the junctions. It is concluded that the applied dual-task method is sensitive to the variation in drivers' cognitive load caused by variations in the demands of the driving task.(Author/publisher).
Abstract