The Interactive Highway Safety Design Model (IHSDM) is a suite of software analysis tools for evaluating safety and operational effects of geometric design in the highway project development process.  The Model was developed under contract by the FHWA

The scope of the current release of IHSDM is two-lane rural highways. 

IHSDM evaluates existing and proposed alternative highway geometric designs and provides quantitative information on their expected safety and operational performance.

IHSDM can check designs against relevant design policy values, estimate the crash frequency expected for a specified geometric design, and estimate other safety and operational performance measures (e.g., 85th percentile speed and percent time spent following) to help diagnose factors that contribute to expected safety performance.

WSDOT is implementing the IHSDM suite for statewide use in spring 2004.   Work on two-lane rural highways comprises about seven percent of the overall WSDOT construction program.  The software will be made available on the engineering applications menu and training will follow from project development trainers.  

WSDOT Design Policy Adjustments for the Policy Review Module

IHSDM Training Project

n   The Policy Review Module 

n   The Crash Prediction Module

n   The Design Consistency Module

n   The Intersection Review Module

n    The Traffic Analysis Module  

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