Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

The latest general information on the Coronavirus Disease 2019 (COVID-19) is available on Coronavirus.gov. For USDOT specific COVID-19 resources, please visit our page.

United States Department of Transportation United States Department of Transportation
OFFICE OF RESEARCH, DEVELOPMENT, AND TECHNOLOGY AT THE TURNER-FAIRBANK HIGHWAY RESEARCH CENTER

Modules

The Interactive Highway Safety Design Model (IHSDM) suite of software analysis tools includes five evaluation modules and an Economic Analyses (EA) Tool:

  1. Crash Prediction Module: Estimates the expected frequency of crashes on a highway using geometric design and traffic characteristics.
  2. Design Consistency Module: Estimates the magnitude of potential speed inconsistencies to help identify and diagnose safety concerns at horizontal curves.
  3. Policy Review Module: Checks highway segment design elements relative to design policy.
  4. Traffic Analysis Module: Estimates operational quality-of-service measures for a highway under current or projected future traffic flows.
  5. Driver/Vehicle Module: Estimates a driver’s speed and path along a highway and corresponding measures of vehicle dynamics.

The IHSDM – HSM Predictive Method 2021 Release Crash Prediction Module includes capabilities to evaluate rural two-lane highways, rural multilane highways, urban/suburban arterials, freeway segments, freeway ramps/interchanges (including ramps, collector-distributor (C-D) roads, and ramp terminals), and roundabouts. The Policy Review Module applies to rural two-lane and rural multilane highways, while the other evaluation modules are only applicable to rural two-lane highways.

The EA Tool allows IHSDM users to perform economic analyses within IHSDM, using Crash Prediction Module evaluation results (i.e., crash frequencies and severities).

For additional information contact:

In-Kyu Lim
Office of Safety Research and Development
Turner-Fairbank Highway Research Center
Federal Highway Administration
6300 Georgetown Pike
McLean, VA 22101
in-kyu.lim@dot.gov

Last updated: Thursday, September 9, 2021