This article considers the impact of roundabouts on pedestrian travel of individuals who are blind. It describes two experiments about street crossing under conditions of free flowing traffic, with a focus on modern roundabout intersections. The first experiment was conducted at three roundabouts, which varied in size and traffic volume. Six totally blind and six sighted adults judged whether gaps in traffic were long enough to permit crossing to the median, or splitter, island before another vehicle arrived. Gap distributions and measures of judgment quality are reported. The blind participants were nearly 2.5 times less likely to make correct judgments than sighted participants, took longer to detect crossable gaps, and were more likely to miss crossable gaps altogether. These differences were only significant at the two higher volume roundabouts. Researchers in the second experiment evaluated the response of drivers to pedestrians with and without such mobility devices as long canes and dog guides. This experiment was performed at a single-lane roundabout, a midblock crossing, and a two-way-stop-controlled intersection. Site-specific characteristics had a greater impact on drivers' yielding than did a mobility device. The findings of the first experiment suggest that crosswalks at roundabouts vary widely in the safety they afford to pedestrians. The results of the second experiment suggest that at some roundabouts, hearing-based judgments about when to initiate a street crossing may be more risky and inefficient than vision-based judgments. Applications of these studies include identifying intersections that may require sufficient modification for increased accessibility to blind pedestrians.
Samenvatting