The objective of the research is to develop implementable methods to incorporate the effects of traffic speeds on the prediction of crash frequency and severity. The proposed methods should be applicable to different roadway facility types, in a format compatible with HSM methods to support the work of state departments of transportation (DOTs) and other users of the manual. PHASE I Task 1. Conduct a comprehensive review of domestic and international research, guidance, models, and other innovative approaches with the potential to address traffic speed effects in highway safety analysis. Summarize how speed is incorporated in related predictive tools. Identify gaps, limitations, and promising methodologies that could be incorporated in the HSM. Task 2. Identify and evaluate data sources that could help develop crash prediction models incorporating speed effects (potential metrics include but not limited to mean, variance, and 85th percentile of operating speed).
