Distortion of drivers' estimates of automobile speed as a function of speed adaptation

10 male undergraduate drivers made 4 estimates of 40 mph speed after varying amounts of exposure to an adapting speed of 70 mph. The influence of these amounts of exposure to the adapting speed on speed judgments was studied, and a significant (p < .01) upward distortion of estimations of 40 mph was found to occur as a function of exposure to the adapting speed. The eta between treatment conditions and speed estimates was .72, and r was .71. The implications of results for accident rates and highway construction are discussed. (15 ref.)