Highway Safety Manual, First Edition

The Highway Safety Manual (HSM) introduces science-based technical approaches to conducting quantitative safety analyses. For the first time—practitioners using the HSM at the state, county, metropolitan planning organization, and local levels will be able to quantitatively evaluate safety management efforts alongside other transportation performance measures such as traffic operations, environmental impacts, and construction costs. This ground-breaking AASHTO publication was funded by the National Cooperative Highway Research Program (NCHRP) and developed based on NCHRP research, with guidance and review by the TRB Task Force on the Development of the Highway Safety Manual. The manual provides practitioners with: methods for developing and evaluating roadway safety management programs; a predictive method to estimate crash frequency and severity; and a catalog of crash modification factors for a variety of geometric and operations treatment types.