IHSDM-Related Initiatives

Two related initiatives share with IHSDM the goal of providing quantitative safety analysis tools to decision makers:

• Highway Safety Manual
• SafetyAnalyst

The Highway Safety Manual is a Transportation Research Board and AASHTO initiative (published by AASHTO) to provide the best factual information and tools in a useful and widely accepted form and to facilitate roadway design and operational decisions based upon explicit consideration of their safety consequences. The HSM is organized into four parts:

1. Introduction and Fundamentals
2. Roadway Safety Management Process
3. Predictive Methods (see table below comparing HSM and IHSDM)
4. Crash Modification Factors

The following table compares the types of predictive methods and types of facilities targeted by the HSM and IHSDM. The first edition of the HSM, published in June 2010, provides predictive methods for rural two-lane highways, rural multilane highways, and urban and suburban arterials. With the 2009 Crash Prediction Module Beta Release (June 30, 2009), FHWA expanded the scope of IHSDM to include the HSM crash prediction methods for multilane rural highways and urban and suburban arterials. The Crash Prediction Module of the IHSDM – HSM Predictive Method 2012 Release is a faithful software implementation of Part C of the 1^st Edition HSM, containing predictive methods for rural two-lane highways, rural multilane highways, and urban and suburban arterials. In addition, the 2012 Release includes a Beta version of predictive methods for freeway segments, based on draft HSM materials. A Calibration Utility assists agencies in implementing the calibration procedures described in the Appendix to Part C of the HSM..

The SafetyAnalyst was developed by FHWA and is now an AASHTOWare product. It provides state-of-the art analytical tools for use in the decision-making process to identify and manage a systemwide program of site-specific improvements to enhance highway safety by cost-effective means. The SafetyAnalyst includes tools for:

• Network screening
• Diagnosis and countermeasure selection
• Economic appraisal and priority ranking
• Evaluation of implemented improvements

The following table compares the scope of and type of decisions targeted by the SafetyAnalyst and IHSDM.