Three experiments examined some of the factors that might affect motorcyclists' conspicuity to other road users. In each case, subjects saw a sequence of slides showing traffic, some of which contained a motorcyclist. A record was taken of their reaction times to decide whether or not a motorcyclist was present in each slide. Experiments 1 and 2 examined the effects on conspicuity of headlight use, type of clothing, distance of motorcyclist from viewer, and driving situation (urban or semi-rural). Experiment 3 looked more closely at environmental influences on motorcyclist conspicuity, systematically varying the level of background `clutter' behind the motorcyclist. All three experiments indicate that the effectiveness of the conspicuity aids used, especially clothing, may depend on the situation in which the motorcyclist was located: bright clothing and headlight use may not be infallible aids to conspicuity. Brightness contrast between the motorcyclist and the surroundings may be more important as a determinant of conspicuity than the motorcyclist's brightness per se. Motorcyclists' conspicuity is a more complex issue than has hitherto been acknowledged. (A)
Abstract