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Interactive Highway Safety Design Model (IHSDM): Software Download

Click the link to download the IHSDM 2021 software release (version 17.0.0; September 2021). 

The IHSDM—which supports the Federal Highway Administration's Data-Driven Safety Analysis initiative—includes five evaluation modules (i.e., Crash Prediction, Design Consistency, Policy Review, Traffic Analysis, and Driver/Vehicle), as well as an Economic Analyses Tool. 

To the extent possible, the Crash Prediction Module (CPM) includes a faithful implementation of Part C (Predictive Method) of the American Association of State Highway Transportation Officials' 1st Edition Highway Safety Manual (HSM) for evaluating rural two-lane highways, rural multilane highways, and urban/suburban arterials, as well as HSM 2014 Supplement materials on freeway segments and freeway ramps/interchanges, and prediction methods for roundabouts and six-or-more lane and one-way urban/suburban arterials (developed under NCHRP Project 17-70  and NCHRP Project 17-58, respectively, and intended for inclusion in the future 2nd Edition HSM (HSM2)). 

IHSDM 2021 enhancements include new crash prediction models for the following intersection types, which were developed under NCHRP project 17-68 (Intersection Crash Prediction Methods for the Highway Safety Manual) for inclusion in the future HSM2:

  • Rural and urban all-way stop-controlled intersections.
  • Rural and urban three-leg intersections where the through movement makes a turning maneuver at the intersection.
  • Rural three-leg intersections with signal control, for both two-lane and multilane highways.
  • Intersections on high-speed urban and suburban arterials (i.e., roadways with speed limits greater than or equal to 50 mph).
  • Urban five-leg intersections with signal control.
  • Crossroad ramp terminals at single-point diamond interchanges.
  • Crossroad ramp terminals at tight diamond interchanges.

IHSDM Help Browser/Documentation

After downloading/installing IHSDM and opening the software, the IHSDM Help Browser (documentation) can be accessed via Help > Help Browser from the main IHSDM menu.

However, the contents of the Help Browser might not display for some users due to Windows 10 security issues. If this occurs, please contact the IHSDM Support team at for work-around instructions.

Help Browser contents are organized by main topics, including:

  • Release Notes for the 2021 Public Release.
  • Frequently Asked Questions (FAQs).
  • IHSDM Overview
  • Acronyms and Abbreviations.
  • Installation and Configuration.
  • System Administration.
  • Data Considerations.
  • IHSDM Interface and Data Organization.
  • IHSDM Workflow.
  • Engineers Manuals.
  • Economic Analyses Tool (EA Tool). 

In addition, a Tutorial provides users with an overview of using the IHSDM software.

Essential IHSDM Information

Downloading and Installing IHSDM

Frequently Asked Questions

Resources (Technical Support, Training, and More)


The Federal Highway Administration (FHWA) recently acquired the .gov domain for the Interactive Highway Safety Design Model (IHSDM) program. Although FHWA used to be associated with the domain name, it was recently purchased by another entity unrelated to FHWA. As such, FHWA is no longer affiliated with the .org site and thus not associated with any content that appears on the .org domain name.