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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 and Operations Research and Development
Turner-Fairbank Highway Research Center
Federal Highway Administration
6300 Georgetown Pike
McLean, VA 22101