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Interactive Highway Safety Design Model (IHSDM): Overview

IHSDM is a suite of software analysis tools used to evaluate the safety and operational effects of geometric design decisions on highways.

IHSDM is a decision-support tool that provides estimates of a highway design's expected safety and operational performance. Results of the IHSDM support decisionmaking in the highway design process. Intended users include highway project managers, designers, and traffic and safety reviewers in State and local highway agencies and in engineering consulting firms.

The IHSDM—which supports the Federal Highway Administration's (FHWA's) Data-Driven Safety Analysis (DDSA) 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. This website provides a link to download the software, summarizes the capabilities and applications of the IHSDM evaluation modules, and provides a library of the research reports documenting their development.

Now Available: The IHSDM – Highway Safety Manual (HSM) Predictive Method 2021 Release (version 17.0.0, September 2021)

The IHSDM – HSM Predictive Method 2021 Release (version 17.0.0, September 2021) may be downloaded free of charge via the Software Download page. User technical support is also available free of charge at and 202-493-3407. IHSDM-related training is offered by the FHWA Resource Center and through the FHWA’s National Highway Institute

Development of the IHSDM is coordinated with the HSM, developed by the Transportation Research Board and published by the American Association of State Highway and Transportation Officials.

NEW: On October 18, 2021 FHWA hosted a Data-Driven Safety Analysis (DDSA) webinar on IHSDM 2021 - New Intersection Models Support DDSA. A recording of the webinar is available here.

Check Out the Latest IHSDM Videos

IHSDM Part 1: Capabilities and Navigation


IHSDM Part 2: Data Entry


IHSDM Part 3: Crash Prediction Module and Economic Analysis Tool


Last updated: Tuesday, December 7, 2021