Grade-separated crossings are widely used to accommodate pedestrian crossings atrnhazardous locations when at-grade solutions are not feasible. They are used primarilyrnto segregate pedestrian populations from automobiles, enhance accessibility andrnconnectivity for pedestrians to nearby local activity centers, and improve therntransportation facility’s overall level of service. Due to cost, it is important for decisionrnmakers to present qualitative determinations justifying the decision to implement thesernstructures. This report presents an overview of research findings concerning pedestrianrncrossing behavior, applicability of grade-separated crossings (primarily overheadrncrossings), their justification, design concerns, and possible shortcomings in an attemptrnto offer directives on grade-separated crossings.rnLiterature sources were reviewed to determine criteria used in developing warrants andrnconditions used for pedestrian bridge implementation. An overview of driver-pedestrianrninteraction was provided to illustrate the concerns relating crash data and at-graderncrossings. Warrants and criteria were compiled and detailed to provide insight onrnrequirements and threshold values. Bridge requirements were then summarized tornhighlight options, specifications, and design considerations. Warranting criteria forrnoverpass crossings are not uniform and many decisions for implementation are basedrnon the locations of schools or fatal crashes. The research reviewed for this reportrnprovided insight on pedestrian activity, pedestrian bridge specifications, and concludedrnthat Average Daily Traffic and Average Daily Pedestrians were sufficient indicators forrnplacement of grade-separated crossings.
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