| The effects of information on driver judgment of curve sharpness were investigated by field experiment. Sixteen curves were chosen from actual roads、 with 80 subjects performing a driving test on the curves in daytime and at night. To determine the effects of information provision method on judgment of curve sharpness、 four methods were proposed: no special information provision、 provision by paper map、 provision by car navigation system、 and provision by proposed curve warning sign indicated by onboard LCD display. Each subject performed one round trip on the test section. The subjects were required to judge each upcoming curve as very sharp、 sharp or gentle. After passing through each curve、 the subjects were asked to reevaluate their estimation as underestimated、 accurately estimated or overestimated. The experiment clarified the effects of information provision method on subjective judgment of curve sharpness. Information provision potentially have a positive effect on subjective judgment. However、 negative driving behavior (rapid speed reduction) was observed at sharp downward curves、 especially for provision by car navigation system. |
