Calibrating Pedestrian Level-of-Service Metrics with 3-D Visualization

Abstract

Unlike the case with airport terminals or the central business district, the quality of suburban pedestrian facilities is most likely affected less by congestion and more by safety, the walking environment, and aesthetics. Because the Highway Capacity Manual does not explicitly capture such factors when measuring pedestrian level of service (LOS), researchers have proposed innovative rating scales that do. These scales use either measurable characteristics, such as walkway width, median openings, and signalization parameters, or user perceptions, such as continuity and convenience, to rate a pedestrian facility. Unfortunately, the results of these scales are not always easy to interpret. For example, in a scaling system for pedestrian facilities in which a raised curb median counts 6 points and a blinking pedestrian-crossing signal counts 3 points, the developers of the scale believed that the median would be twice as valuable to pedestrians as the crossing signal. But would pedestrians agree? A scaling system was developed for pedestrian LOS and calibrated using visualization (computer-aided modeling techniques consisting of still shots and animations). Subjects’ perceived ratings of a pedestrian facility after they viewed still pictures and animations of the facility were compared with the computed rating of the facility from an LOS scale. The chief value of this method is that it helps ensure that pedestrian crossing needs are systematically considered and that engineers, planners, and the public agree on the calibration of a pedestrian LOS scale. The methodology is also applicable in urban areas where pedestrian needs beyond physical capacity are to be explicitly considered. The approach is original in that visualization as a simulation and data analysis tool was used to calibrate a pedestrian LOS scale.