Roadway safety countermeasures are often implemented as a reaction to an automobile safety concern without a clear understanding of the impacts, both positive and negative, on other road users. Pedestrian and bicyclist fatalities have been increasing and now account for more than 15% of all roadway fatalities; therefore, it is appropriate to examine tradeoffs in safety and mobility between motorists and pedestrians and bicyclists that might be contributing to the increase.
For instance, countermeasures such as signalization treatments, provision of turn lanes, wider travel lanes, rumble strips, and access control may negatively impact pedestrians and bicyclists by increasing motor vehicle speeds and throughput, increasing crosswalk distances, adding conflict points, increasing delay, or restricting pedestrian and bicycle mobility. As an example, the growing use of roundabouts may improve motor vehicle operations and safety, but can increase pedestrian travel distance.
The objective of this research is to (1) develop a decision tool (e.g., checklists, matrices) to identify tradeoffs in safety and mobility in different types of facilities between motorists and pedestrians and bicyclists arising from motor vehicle safety countermeasures; and (2) develop future research needs.
The research should include, but not be limited to, the following:
- Identify candidate countermeasures: review literature (including the Crash Modification Factors Clearinghouse) and consult with subject matter experts to identify the highest priority motor vehicle safety countermeasures to explore in this project.
- Conduct in-depth reviews of countermeasures: synthesize the literature, guidelines, and other materials to identify tradeoffs related to motorist, pedestrian, and bicyclist safety, and other issues such as convenience (e.g., delay and travel distance for pedestrians), and Level of Service.
- Develop the decision tool and research recommendations: develop checklists/matrices to reflect tradeoffs found in #2; develop a prioritized list of research for the AASHTO Technical Committee on Non-motorized Transportation.
The final report is available at https://onlinepubs.trb.org/Onlinepubs/NCHRP/docs/NCHRP20-07Task393Final.pdf.
The decision tool is available at https://onlinepubs.trb.org/Onlinepubs/NCHRP/docs/NCHRP20-07Task393DecisionTool.xlsm.
The tool user guide is available at https://onlinepubs.trb.org/Onlinepubs/NCHRP/docs/NCHRP20-07Task393UserGuide.pdf.