Space Syntax: Innovative Pedestrian Volume Modeling Tool for Pedestrian Safety

Abstract

An innovative pedestrian modeling technique known as Space Syntax is described. The technique was used to create estimates of pedestrian volumes for the city of Oakland, California. Pedestrian exposure rates were calculated, and a relative risk index for the city's first pedestrian master plan was created with those estimates. A major challenge facing planners, transportation engineers, and pedestrian-safety advocates is the lack of detailed, high-quality pedestrian-exposure data. Exposure is defined as the rate of contact with a potentially harmful agent or event. Pedestrian exposure is therefore defined as the rate of pedestrian contact with potentially harmful situations involving moving vehicles (e.g., crossing an intersection). Pedestrian risk is defined as the probability that a pedestrian-vehicle collision will occur, based on the rate of exposure. To estimate exposure, pedestrian volume measurements must be made, but such measurements are not easily obtainable. In the absence of accurate exposure data, pedestrian-safety decisions are often made by estimation, rule of thumb, or political influence and result in mixed and potentially less effective outcomes. The value of the Space Syntax volume-modeling approach for generating estimates of pedestrian exposure is explored with the city of Oakland as a case study. The method's theoretical background, data requirements, implementation, and results are discussed. It is suggested that the output of the model—citywide pedestrian volume estimates—is useful to pedestrians, planners, and transportation engineers. The value of the pedestrian-exposure concept for the planning professional is discussed.