Environmental Review Toolkit
NEPA and Project Development

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:

  • NEPA training programs;
  • References for NEPA regulation and guidance; and
  • Analytical tools and resources for identifying and addressing project-level safety issues.

A.1 NEPA Training

A.2 Safety Training

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

  • Safety Professional Capacity Building;
  • National Highway Institute, including courses on Transportation Safety Planning and other topics;
  • Improving Safety of Horizontal Curves;
  • Designing for Pedestrian Safety;
  • Developing a Pedestrian Safety Action Plan;
  • Planning and Designing for Pedestrian Safety;
  • Application of Crash Reduction Factors (CRF);
  • Science of Crash Reduction Factors;
  • Supply and Demand for Highway Safety Professionals in the Public Sector;
  • Core Competencies for Highway Safety Professionals;
  • Model Safety Curricula – Safety 101; and
  • Professional Development – Safety 101.

A.3 References for NEPA Regulation and Guidance


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 for Implementing the Procedural Provisions of the National Environmental Policy Act” – 40 CFR Parts 1500-1508, November 29, 1978 (Council on Environmental Quality – CEQ); and
  • ”Environmental Impact and Related Procedures“ 23 CFR 771, August 28, 1987 (FHWA), http://environment.fhwa.dot.gov/projdev/tdmpdo.asp.
FHWA Guidance
Other Guidance
  • Questions and Answers about NEPA Regulations, Council on Environmental Quality (CEQ) Memorandum, March 16, 1981.
  • The RED BOOK – Applying the Section 404 Permit Process to Federal-Aid Highway Projects, FHWA, et al., September 1988.
  • FHWA Environmental Guidebook (primarily an internal document) – An all-inclusive compendium of environmental guidance information that includes the following:
    • Section 4(f) Policy Paper, October 5, 1987, as updated June 7, 1989;
    • Transportation Enhancement Activities, FHWA Memorandum, April 24, 1992;
    • Cooperating Agencies, FHWA Memorandum, March 19, 1992; and
    • Purpose-and-Need, FHWA Memorandum, September 18, 1990.
  • NEPA and Transportation Decision-Making – Project Development and Documentation Overview, August 21, 1992, http://environment.fhwa.dot.gov/projdev/tdmpdo.asp.

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:

  • Description of the problem.
  • Strategies for addressing the problem (strategies from multiple Es are typically included), information on expected effectiveness, keys to success, potential difficulties, associated measures and data, organizational and policy issues, cost issues, legislative needs, and other topics.
  • A list of related strategies for “creating a truly comprehensive approach” – this typically includes general discussion of how all the “Es” can get involved in implementing the emphasis area.
  • An index of strategies by effectiveness (proven, tried, and experimental); implementation timeframe; and relative cost.

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:

  • Identify sites with the most potential for crash frequency or severity reduction;
  • Identify factors contributing to crashes and associated potential countermeasures to address these issues;
  • Evaluate the crash reduction benefits of implemented treatments;
  • Conduct economic appraisals of improvements to prioritize projects;
  • Calculate the effect of various design alternatives on crash frequency and severity; and
  • Estimate potential crash frequency and severity on highway networks, and the potential effects of transportation decisions on crashes.

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:

  • 5 Stars – Demonstrated effective by several high-quality evaluations with consistent results.
  • 4 Stars – Demonstrated effective in certain situations.
  • 3 Stars – Likely effective based on balance of evidence from high-quality evaluations or other sources.
  • 2 Stars – Effectiveness still undetermined; different methods of implementing this countermeasure produce different results.
  • 1 Star – Limited or no high-quality evaluation evidence.

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

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:

  • LOSS-I – Indicates low potential for crash reduction;
  • LOSS-II – Indicates low to moderate potential for crash reduction;
  • LOSS-III – Indicates moderate to high potential for crash reduction; and
  • LOSS-IV – Indicates high potential for crash reduction.

The LOSS method is intended to:

  • Help bring about consensus on the subject of the magnitude of safety problems for different classes of roads;
  • Bring the perception of roadway safety in line with reality of safety performance of a specific facility; and
  • Provide a frame of reference from a safety perspective for planning major corridor improvements.

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