​What's New

New Errata for the HSM - technical corrections to several items have been added to the HSM errata. See the March 2016 errata​ for additional information. 

New Chapter for the HSM – The Enhanced Safety Prediction Methodology and Analysis Tool for Freeways and Interchanges (​​NCHRP 17-45). Research from the National Highway Cooperative Research Program (NCHRP) resulted in safety prediction methodologies for freeways and interchanges. These methodologies are designed to address a wide range of freeway and interchange conditions, such as freeway-freeway systems, freeway-crossroad service interchanges, and crossroad ramp terminals that are signalized or two-way stop controlled.

For more information contact Kelly Hardy, AASHTO Senior Engineering Program Manager, at khardy@aashto.org.