Comment:
Summary of basic definitions and concepts for risk and exposure. Contextualizes terms in pedestrian and bicyclist safety analysis.

Last Updated (Year): 2017

Year Produced: 2017

Abstract:

This report summarizes the variety of methods used to estimate and evaluate exposure to risk in pedestrian and bicyclist safety analyses. In the literature, the most common definition of risk was a measure of the probability of a crash to occur given exposure to potential crash events. There was also consensus on a theoretical definition of exposure as a measure of the number of potential opportunities for a crash to occur. However, there is wide divergence on operational definitions of exposure, and an even wider range of exposure measures being used in practice. Geographic scale is a critical element in most exposure analyses, and most analyses reviewed could be grouped into one of four scales: 1) regional (e.g., city, county, state);2) network (e.g., traffic analysis zone, Census tract, Census block group);3) road segment;and, 4) point (e.g., mid-block or intersection street crossing). This report summarizes numerous examples of exposure estimation methods at these different geographic scales, and discusses the data sources and analytic methods used to estimate exposure in these different geographic scales. Other pedestrian and bicyclist risk factors besides exposure also are cataloged.

For:Walking, Biking

The E's:Evaluation

Ped Bike Activity:

• Assessment

Ped Bike Topic:

• Safety
• Research
• Forecasting
• Design
• Data
• Assessment
• Analysis

Facility Type:Intersection, Crosswalk

Road Constraints:Multi Lane

Urban Context:Urban, Rural

Resource Type:

• Information

Link to Content Source:

Synthesis of Methods for Estimating Pedestrian and Bicyclist Exposure to Risk a…