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.
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:
- Develop a framework for implementing speed management strategies for pedestrian and bicycle safety on arterials and higher-speed roadways; and
- 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.
PHASE I — Planning
Task 1. Review literature and state-of-the-practice. Establish the range of needs and possible case studies regarding development of a context-driven framework for speed management on arterials and higher-speed roadways, as well as tools for improving safety for pedestrians and bicyclists on these roads. The review shall include current practice at state and local agencies; the National Association of City Transportation Officials (NACTO), the American Association of State Highway and Transportation Officials (AASHTO), and the Institute of Transportation Engineers (ITE) guidelines and standards; and published and unpublished research conducted through the NCHRP, the Federal Highway Administration (FHWA), and other national, international, state, and pooled-fund sponsored research. International best practices and high-level policy documents should be considered for this task as appropriate.
For the purposes of this RFP, 40 mph has been used to define “higher-speed” based on the FHWA Safe Transportation for Every Pedestrian (STEP) guide. However, a different motor vehicle operating speed may be a better indicator of “higher-speed.” This task includes research into the appropriate threshold for higher-speed as it relates to vulnerable road users.
Proposals should include information on how state-of-the-practice will be reviewed (e.g., online surveys, interviews, etc.).
Task 2. Analyze descriptive crash data. Review available crash data to glean more information about the location and types of pedestrian/bicycle crashes that are occurring on arterials and higher-speed roadways in different contexts. Crash analysis should include information from different regions of United States. Proposal should indicate information about the crash data set to be used for this task and how that might be obtained.
Task 3. Propose case study protocol to be developed in Phase II that will cover several approaches to context-driven speed management and context-driven pedestrian and bicycle safety improvements.
- The approaches to context-driven speed management to be studied will be informed by the literature review and crash analysis and may include significant roadway design/changes (e.g., moving a curb line to reduce the number of lanes, introducing profile changes, etc.) or less-intensive approaches such as changes to signal timing, traffic control devices, pavement markings, and enforcement.
- The approaches to context-driven safety improvements for pedestrians and bicyclists on arterials and higher-speed roadways to be studied will also be informed by the previous tasks and may include significant roadway changes or less-intensive approaches. These treatments may or may not have been implemented in conjunction with speed management.
- Case study protocol should be focused on clearly identifying the effectiveness of the treatments being reviewed. Measures of effectiveness may include how much speeds were reduced, evidence of improved safety (both perceived and actual), and documentation of how travel volumes and delays have changed for all modes.
- The proposal should include information on how case studies locations will be selected. Case studies should include a combination of corridor-long interventions and spot treatments. Case studies that include more than one aspect of the safe system approach (e.g., design, education, technology, enforcement, etc.) are desirable.
Task 4. Develop outline and concepts for a guide that identifies how treatments and case studies will be discussed. The outline should indicate how practitioners will be able to apply guidance on speed management and pedestrian/bicycle safety treatments on higher-speed roadways.
Task 5. Prepare Interim Report No. 1 documenting the results of Tasks 1 through 4 and provide an updated plan for the remainder of the research no later than 6 months after contract award. The updated plan must describe the process and rationale for the work proposed for Phases II and III.
PHASE II — Research Implementation
Task 6. Execute the approved Task 3 case studies according to the approved Interim Report No.1 work plan.
Task 7. Develop a draft guide based on comments from Interim Report No. 1 with specific recommendations for implementing effective motor vehicle speed management and appropriate safety improvements for pedestrians and bicyclists on roadways with higher motor vehicle operating speeds (40 mph or more) or motor vehicle operating speeds that are considered too high for the context.
The guide should include details on strategies implemented at the case study locations, evidence of improved safety (perceived and actual), and other information relevant to practitioners making decisions about potential treatments. The guide may include information that serves as a model for state DOTs or local agencies to develop a jurisdiction-wide approach.
Task 8. Develop a user focus group engagement plan to gather inputs from practitioners from several regions of United States to review the draft guide through an on-line or in-person workshop.
Task 9. Prepare Interim Report No. 2 that documents Tasks 6 through 8 and provide an updated work plan for the remainder of the research. The updated plan must describe the process and rationale for the work proposed for Phase III.
PHASE III — Final Deliverables
Task 10. Present the final draft guide according to approved Interim Report No. 2 to a user focus group with practitioners from several regions of the country and gather feedback to refine the final product.
Task 11. Develop the draft final deliverables revised as appropriate based on the results of the focus group input, including the guide and the following:
- A conduct of research that documents the entire research effort and any lessons learned and recommendations;
- Media and communication materials (presentation, graphics, graphics interchange format (GIF)s, press releases, etc.); and
- A stand-alone technical memorandum titled “Implementation of Research Findings and Products.”
STATUS: A research contractor has been selected for the project. The contracting process is underway.