This report describes two related studies intended to address double-lane roundabout accessibility issues for visually impaired pedestrians. The first study was conducted on a closed course to evaluate the feasibility of a pavement treatment to alert blind pedestrians when vehicles have yielded to them. The second study examined drivers’ yielding behaviour at a two-lane roundabout and the effectiveness of the same roadway treatment in an operational environment. In the first study, there were two experimental conditions: a control condition and a treatment condition in which rumble strip-like devices were placed on the roadway surface. Seven individuals who have severe visual impairments participated. Participants stood at a crosswalk and used hand signals to indicate when they detected vehicles stopping or departing after a stop. Compared to the control condition, the sound strips treatment increased the probability of detecting stopped vehicles, and decreased by more than a second the amount of time needed to make a detection; however, the treatment did not reduce the number of false detections. False detections could result in the pedestrian crossing when moving vehicles are approaching the crosswalk. The second study was an experiment conducted at an operating roundabout. In that environment the rumble strip-like treatment was not effective, probably because the majority of vehicles stopped in the circular roadway before crossing over the rumble strips. A Yield to Pedestrians, State Law sign that was placed in the roundabout exit between the two travel lanes resulted in an increase in drivers’ yielding from 11 percent of vehicles in the control condition to 16 percent in the experimental condition. It was concluded that the treatments explored in these studies do not appear promising for double-lane roundabouts, but should be explored further to see if they might work at single-lane crossings. (Author/publisher)
Samenvatting