Currently, there is no commonly accepted or adopted measure of pedestrian and bicyclist exposure. This report presents a methodology for measuring a region’s pedestrian and bicyclist exposure, which is defined as 100 million pedestrian/bicyclist mi (161 million pedestrian/bicyclist km) of roadway (or other motor vehicle shared facility) traveled. A method for implementing the exposure measure is described for various shared facility types that are characteristic to the urban environment of Washington, DC. These facilities include three types of intersections (signalized, stop-controlled (all-way), and partially stop-controlled) as well as midblock road segments, driveways, alleys, parking lots, parking garages, school areas, and areas with playing/dashing/working in the roadway. A pilot study demonstrated the feasibility of the method at seven sites in Washington, DC, in 2006. In 2007, the methodology was implemented on a larger scale to estimate the annual pedestrian and bicyclist exposure in Washington, DC, which was 0.80 hundred million mi (1.29 hundred million km) for pedestrian exposure and 0.37 hundred million mi (0.59 hundred million km) for bicyclist exposure. As a result of simplifications in the present data aggregation technique, these particular exposure values are overestimated. However, procedural changes are suggested to correct this issue. Within the constraints of this study, both the feasibility and scalability of the methodology were successfully demonstrated for a relatively large urban environment. The results indicate that the methodology has the potential to be used to collect exposure data that are not currently readily available to the pedestrian and bicycle safety community. Although further refinement and validation are still needed, the methodology provides a possible initial foundation to develop a national unit of exposure for pedestrians and bicyclists. (Author/publisher)
Abstract