More than 4,000 pedestrians and 700 bicyclists were killed in collisions with motor vehicles in the United States in 2012. Improving pedestrian and bicycle facilities at intersections is clearly a critical safety need. Pedestrian crashes often occur at intersections involving automobiles turning left and striking pedestrians in the far crosswalk, or automobiles turning right and striking pedestrians in the near or far crosswalk. This includes situations where drivers are allowed to make a right turn on red. Of particular concern for bicyclist safety at intersections is the conflict between bicyclists traveling straight and automobiles from the opposite direction turning left across the path of bicyclists. In addition, there are often conflicts between bicyclists traveling straight and automobiles from the same direction turning right across the path of bicyclists. A third common type of bicycle crash involves motorists emerging from side streets and not yielding to through-moving bicyclists.
Despite the widespread acknowledgement of these problems, and the growing use of bicycles in metropolitan areas, transportation engineers and planners still lack definitive guidance on which types of intersection designs and operational treatments have the greatest safety benefits for pedestrians and bicyclists, nor the most appropriate situation in which each should be applied. Engineering judgment will still be needed in many cases, but better guidance for applying typical and innovative intersection design treatments will help improve pedestrian and bicycle safety.
The objective of this research is to develop guidance for transportation practitioners to improve pedestrian and bicycle safety at intersections through design and operational treatments that (1) identifies and evaluates current practices, and emerging technologies and trends, in the U.S. and internationally; (2) describes current best practices for measuring the effectiveness of such intersection treatments; (3) evaluates safety outcomes of specific intersection treatments using quantitative measures; and (4) identifies and ranks strategies, processes, and relationships that could accelerate the adoption of improved pedestrian and bicycle intersection design and operational treatments.
The approaches to evaluate pedestrian and bicycle treatments can be separate, but implementation of the treatments should be coordinated. The guidance should address a broad range of issues related to improved pedestrian and bicycle safety at intersections such as, but not limited to the following:
Identifying typical and innovative design treatments to improve the safety of pedestrians and bicyclists at intersections (e.g., signalized, unsignalized, midblock crossings, roundabouts, ramps);
Identifying common motor vehicle/pedestrian, motor vehicle/bicyclist crash types and severity at intersections;
Identifying differences in temporal or spatial settings (e.g., urban, suburban, rural, land use);
Developing quantitative safety analysis techniques for evaluating design and operational treatments (e.g., conflict studies, crash analysis, injury severity, behavioral analysis, naturalistic driving studies):
-- Considering specific bike design and operational elements (e.g., bike boxes, cycle tracks, separated bike lanes, colored pavement, bicycle signals);
-- Considering specific pedestrian design and operational elements (e.g., refuge islands, curb extensions, signals, prohibited right turn on red, road diets, traffic calming, signal operations);
Documenting benefits and trade-offs of pedestrian and bicycle intersection design versus operational treatments;
Suggesting countermeasures and criteria for implementation; and
Providing a foundation for future data collection and more rigorous studies that produce Crash Modification Factors (CMFs).
While the guidance should be directly applicable to most situations, it should also outline decision-making processes and criteria that would assist agencies in identifying flexible solutions.
A kick-off teleconference of the research team and NCHRP shall be scheduled within 1 month of the contract’s execution. The work plan must be divided into 2 phases with tasks, with each task described in detail. There must be an interim report and a face-to-face meeting with NCHRP to discuss an interim report that (1) identifies and evaluates current practices, and emerging technologies and trends, in the U.S. and internationally; and (2) describes current best practices for measuring the effectiveness of such intersection treatments; the proposed research approach to evaluate safety outcomes of specific intersection treatments using quantitative measures; and an outline of the guidance. No work shall be performed on Phase 2 without NCHRP approval. Phase 2 shall include data collection, analysis, and development of the guidance. The NCHRP is seeking insights of proposers on how to best gather feedback from transportation practitioners on the efficacy of the guidance. The final deliverables will include (1) the guidance for transportation practitioners to improve pedestrian and bicycle safety at intersections through design and operational treatments that (a) identifies and evaluates current practices, and emerging technologies and trends, in the U.S. and internationally; (b) evaluates current best practices for measuring the effectiveness of such intersection treatments; (c) evaluates safety outcomes of specific intersection treatments using quantitative measures; and (d) identifies and ranks strategies, processes, and relationships that could accelerate the adoption of pedestrian and bicycle intersection design and operational treatments; (2) a final report documenting the entire project, incorporating all other specified deliverables of the research; (3) a stand-alone executive summary that summarizes the research; (4) a PowerPoint presentation of the guidance that can be tailored for specific audiences; (5) a video product to inform practitioners of the research; (6) recommendations on needs and priorities for additional research; and (7) a stand-alone technical memorandum titled “Implementation of Research Findings and Products”.