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The Traffic Analysis Module uses the TWOPAS traffic simulation model to estimate traffic quality-of-service measures for an existing or proposed design under current or projected future traffic flows. The traffic analysis module facilitates use of TWOPAS by feeding it the roadway geometry data...
The Policy Review Module checks roadway-segment design elements for compliance with relevant highway geometric design policies. The module provides electronic files replicating quantitative policy values specified by the American Association of State Highway and Transportation Officials (AASHTO...
The Design Consistency Module (DCM) helps diagnose safety concerns at horizontal curves. Crashes on two-lane rural highways are over-represented at horizontal curves, and speed inconsistencies are a common contributing factor to crashes on curves. This module provides estimates of...
The Crash Prediction Module (CPM) includes an implementation of the crash prediction methods documented in part C of the American Association of State Highway and Transportation Officials’ (AASHTO) First Edition Highway Safety Manual (HSM). CPM includes capabilities to evaluate rural two-lane...
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-...
The Highway Safety Design Manual (HSM) shares the Interactive Highway Safety Design Model’s (IHSDM’s) goal of providing quantitative safety analysis tools to decisionmakers.
The HSM is a Transportation Research Board (TRB) and...
The Interactive Highway Safety Design Model (IHSDM) suite of software analysis tools includes five evaluation modules and an Economic Analyses (EA) Tool:
The mission of the Geometric Design Laboratory (GDL) is to support the Office of Safety Research and Development in research related to the geometric design of roadways and the impacts on safety. The GDL provides technical support to develop, maintain, and...
Welcome to the Interactive Highway Safety Design Model (IHSDM) Frequently Asked Questions list. Here you will find the links to each section of the FAQ to help you download, install, and use this software.
To request user technical support, contact:
IHSDM Help Line: (202) 493-3407
IHSDM Support Email: IHSDM.Support@dot.gov
For other information about IHSDM, contact:
In-Kyu Lim
Office of Safety and Operations Research...