BACKGROUND

While the role of speed in traffic crashes is a complex topic, research has found unequivocally that higher motor vehicle speeds lead to higher injury severity for vulnerable road users. Notably, the risk of serious injury or fatality for pedestrians increases dramatically as vehicle speed on impact increases, with a roughly 73% chance of fatality or severe injury at 40 mph (as noted in B.C. Tefft's article, "Impact Speed and a Pedestrian's Risk of Severe Injury or Death," published in Accident Analysis & Prevention, 2013. https://doi.org/10.1016/j.aap.2012.07.022) . It is also clear that drivers traveling at higher speeds have less time to react to unexpected situations, less recovery time if distracted, and longer braking distance, which contributes to crashes. Research has found that arterials and higher-speed roadways are associated with increased frequency and severity of pedestrian and bicycle crashes.

A Safe System approach to roadway safety requires a robust speed management effort on arterials and higher-speed roadways. On lower-speed roadways, traffic calming strategies with vertical and horizontal deflections (raised speed humps, bumps, chicanes, center turning islands) have been found to be effective speed management treatments. However, solutions for motor vehicle speed management along arterials and higher-speed roadways are more limited and often much more challenging to implement. This research will build on the findings from NCHRP Synthesis 535: Pedestrian Safety Relative to Traffic-Speed Management that focused on lower-speed roadways and indicated that more investigation was needed for higher-speed facilities.

A framework for applying speed management strategies may be a valuable tool for practitioners looking to improve pedestrian and bicyclist safety on arterials and higher-speed roadways. However, speed management may not be practical on all corridors and/or may not result in enough of a reduction in risk for pedestrians and bicyclists. In these instances, other treatments may be necessary to improve safety for people walking and biking within the higher-speed environment.

Research is needed to (1) demonstrate the impacts of speed management efforts on arterials and higher-speed roadways, specifically for people walking and bicycling, and (2) provide clear guidance on successful implementation of other strategies that improve safety for people walking and biking on arterials and higher-speed roadways.

OBJECTIVE

The objective of this research is to develop a guide that can be used as a context-driven framework for motor vehicle speed management and appropriate safety improvements for pedestrians and bicyclists on roadways with high motor vehicle operating speeds (40 mph or more) or motor vehicle operating speeds that are considered too high for the context.

At a minimum, the research team shall:

1. Develop a framework for implementing speed management strategies for pedestrian and bicycle safety on arterials and higher-speed roadways; and
2. Develop a toolbox for safety improvements for pedestrians and bicyclists on arterials and higher-speed roadways.

Accomplishment of the project objective will require at least the following tasks.