Perception of vehicle speed as a function of vehicle size
Previous research suggests that an observer’s ability to detect the motion of an object increases as the size of the object increases. Anecdotal evidence suggests that the opposite is true. In this experiment, 84 subjects watched a videotape of either a motorcycle, a Jeep Cherokee, or a singleaxle dump truck approaching at either 40 km/h or 80 km/h for 4 sec. The subjects were then asked to estimate the time it would take for the vehicle on the tape to hit them if it continued at the same speed. The subjects could accurately discern the difference in speeds, but no effect of vehicle size was found on the subjects’ estimates of the time to collision. Previous researchers used approaching objects with a wide variance in size placed close to the observers. In this experiment, the vehicles were relatively similar in size and were observed from a long distance.
- Baker, C. A., & Steedman, W. C. (1961). Perceived movement in depth as a function of luminance and velocity. Human Factors, 3, 166–173.Google Scholar
- Federal Railroad Administration. (1989). Rail-Highway Crossing Accident/Incident and Inventory Bulletin, No. 11, Calendar Year 1988. Washington, DC: U.S. Department of Transportation.Google Scholar
- Liebowitz, H. W. (1985). Grade crossing accidents and human factors engineering. American Scientist, 73, 558–562.Google Scholar
- Schiff, W. (1965). Perception of impending collision: A study of visually directed avoidant behavior. Psychological Monographs: General and Applied, 79(Serial No. 604).Google Scholar