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FHWA Home / Safety / Transportation Safety Planning (TSP) / Integrating Road Safety into NEPA Analysis

Integrating Road Safety into NEPA Analysis: A Primer for Safety and Environmental Professionals

A. Resources

This section lists several types of resources to assist practitioners in incorporating safety into the NEPA process, including:

A.1 NEPA Training

A.2 Safety Training

The FHWA Office of Safety web site (http://safety.fhwa.dot.gov/) provides links to multiple safety training opportunities, including:

A.3 References for NEPA Regulation and Guidance

Legislation

Federal-Aid Highways, Title 23, United States Code, “Highways,” National Environmental Policy Act of 1969, as amended (NEPA), plus numerous other related statutes and orders, http://environment.fhwa.dot.gov/projdev/tdmpdo.asp.

Regulations

FHWA Guidance

Other Guidance

A.4 Analytical Tools and Resources for Identifying and Addressing Project-Level Safety Issues

Reference Documents

State Strategic Highway Safety Plans

Federal transportation legislation (SAFETEA-LU) requires states to develop a State Strategic Highway Safety Plan (SHSP). The SHSP identifies the state’s most significant safety problems, and provides specific strategies from across the four “Es” of safety (engineering, education, enforcement, emergency response) to address them. Project planners and designers can refer to the SHSP for ideas on how to incorporate safety concepts into project development. Ideally, all safety projects should address a specific problem highlighted by the SHSP.

NCHRP 500 Series

In addition to using SHSPs as a resource, project planners and designers can refer to the NCHRP 500 Series for detailed research on a wide range of safety strategies. The 500 Series consists of more than 20 guides containing strategies for implementing each of the AASHTO’s SHSP priority emphasis areas.

The guides are designed to support implementation of the 4E approach within each emphasis area by providing concrete ideas for how the emphasis area applies to the 4Es. Each guide provides the following information:

Source: http://safety.transportation.org/guides.aspx.

Highway Safety Manual

The purpose of the Highway Safety Manual (HSM) is to provide the best factual information and proven analysis tools for crash frequency prediction. The HSM will facilitate integrating quantitative crash frequency and severity performance measures into roadway planning, design, operations, and maintenance decisions. The primary focus of the HSM is the increased application of analytical tools for assessing the safety impacts of transportation project and program decisions.

The HSM can be used to:

Source: http://safety.fhwa.dot.gov/hsm/factsheet/.

FHWA – Crash Modification Factors Clearinghouse

The FHWA maintains a comprehensive database of available crash modification factors (CMF) for a wide range of safety countermeasures. CMFs include a star rating (one to five stars) indicating their quality.

Source: http://www.cmfclearinghouse.org/.

NCHRP 622 – Effectiveness of Behavioral Highway Safety Countermeasures

The National Cooperative Highway Safety Program Report 622 (Effectiveness of Behavioral Highway Safety Countermeasures) provides information on the effectiveness of educational and enforcement countermeasures. Countermeasures are divided into five categories: proven, likely, uncertain, unknown, and varies.

Source: http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_622.pdf.

Countermeasures That Work: A Highway Safety Countermeasure Guide for State Highway Safety Offices

“Countermeasures that Work” is a guide to assist State Highway Safety Offices (SHSO) in selecting effective, science-based traffic safety countermeasures for highway safety emphasis areas. As with the NCHRP 500 Series, this guide arranges countermeasures under each emphasis area. It then categorizes each safety improvement as a subgroup within each emphasis area, and rates them according to effectiveness. This effectiveness rating is based on published research and consists of five levels:

Source: http://www.ghsa.org/html/publications/countermeasures/.

Software Tools

Safety Analyst

Safety Analyst consists of six software programs to analyze the safety performance of specific sites, to suggest appropriate countermeasures, quantify their expected benefits, and evaluate their effectiveness. These six tools are:

  1. Network Screening Tool – Identifies sites in need of safety improvement;
  2. Diagnosis Tool – Diagnoses the nature of safety problems at specific sites;
  3. Countermeasure Selection Tool – Assists users in selecting countermeasures to reduce crash frequency and severity at specific sites;
  4. Economic Appraisal Tool – Conducts economic appraisals of the costs and safety benefits of countermeasures selected for a specific site;
  5. Priority Ranking Tool – Provides a priority ranking of sites and proposed improvement projects based on the benefit and cost estimates determined by the economic appraisal tool; and
  6. Evaluation Tool – Enables the design and application of well-designed before/after evaluations.
Interactive Highway Safety Design Model (IHSDM)

IHSDM is a suite of software analysis tools for evaluating the safety and operational effects of geometric design decisions on highways. IHSDM is a decision-support tool that checks highway designs against policy values, and provides estimates of a design’s expected safety and operational performance. The IHSDM consists of six evaluation modules:

  1. Crash Prediction – Estimates the frequency of crashes expected on a roadway based on its geometric design and traffic characteristics;
  2. Design Consistency – Helps diagnose safety concerns at horizontal curves;
  3. Intersection Review – Identifies potential safety concerns and possible treatments to address those concerns;
  4. Policy Review – Checks roadway-segment design elements for compliance with relevant highway geometric design policies;
  5. Traffic Analysis – Uses a traffic simulation model to estimate traffic quality of service measures for an existing or proposed design under variable traffic flows; and
  6. Driver/Vehicle – Permits the user to evaluate the drivability of a roadway design, and to identify existing conditions that could result in loss of vehicle control.
Levels of Service of Safety (Kononov and Allery, 2003, Level of Service of Safety Conceptual Blueprint and Analytical Framework, Transportation Research Record, Transportation Research Board, http://diexsys.com/PDF/1840-007.pdf)

The Level of Service of Safety (LOSS) tool was developed by engineers at the Colorado DOT. The concept of Level of Service of Safety uses quantitative measures to characterize the safety of a roadway segment in reference to its expected performance. The LOSS is determined by using the Safety Performance Function to predict the expected number of crashes for a given location, and compare it to the actual number of crashes (including frequency and severity). This is used to rate the road segment as follows:

The LOSS method is intended to:

Page last modified on October 29, 2014
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