Cell Phone Conversation and Relative Crash Risk

Experimental studies are not included because they cannot make valid estimates of actual crash risk, which requires real-world driving data. Experimental studies are conducted in a driving simulator, on a road or track closed to other traffic, and on public roadways, while the driver is under experimental control. The experimenter usually manipulates the timing and demands of secondary tasks, in artificial scenarios not freely chosen by the driver. In addition, experimental studies rarely represent driving conditions, demand levels, and environmental conditions that drivers will actually experience during real-world driving. In contrast, during real-world driving, drivers can choose whether, where, when, and how to engage in a secondary task during the primary driving task. Definitions of Terms