A series of observations and measurements were made as 21 subjects drove their own vehicles in an assortment of naturalistic backing tasks. The tasks were performed on public roads in real world driving conditions. As the subjects performed the eight tasks, the following data were collected: glance direction, hand position, car speed, and distance to object in back of the vehicle. The results provide a set of normative data usable by automotive system designers for the design of backing warning systems, or other products or environments related to backing. The results were divided into glance direction, backing speed, and time-to-collision. Glance directions were found to vary greatly between tasks, and were distributed widely around the vehicle. Elderly drivers demonstrated a preference for using their mirrors and looked over their shoulder less than the young subjects. Except for the extended backing maneuvers, backing speeds averaged around 3 mph. The maximum backing speed for the young drivers was faster than the elderly and males backed faster than females. Time-to- collision values were approximately the same for males and females as well as young and old. Time-to-collision tended to remain relatively constant as the vehicle backed toward an object. The minimum times-to-collision exceeded 1.0 s, and usually exceed 2.0 s. (Author/publisher)
Abstract