U.S. Department of Transportation 1200 New Jersey Avenue SE., Washington, DC 20590

National Highway Traffic Safety Administration

TRAFFIC TECH

Technology Transfer Series

DOT HS 812 479 April 2018

Countermeasures That Work, Ninth Edition

The National Highway Traffic Safety Administration has 

published its ninth edition of Countermeasures That Work. 

The guide is a basic reference to assist State Highway Safety 

Offices (SHSOs) and other professionals interested in highway safety in selecting effective, evidence-based countermeasures for traffic safety problem areas. These areas include:

■ Alcohol- and Drug-Impaired Driving,

■ Seat Belts and Child Restraints,

■ Speeding and Speed Management,

■ Distracted and Drowsy Driving,

■ Motorcycle Safety,

■ Young Drivers,

■ Older Drivers,

■ Pedestrian Safety, and

■ Bicycle Safety.

The guide:

■ Describes major strategies and countermeasures that are 

relevant to SHSOs;

■ Summarizes strategy/countermeasure use, effectiveness, 

costs, and implementation time; and

■ Provides references to the most important research summaries and individual studies.

What’s included: The guide contains a chapter for each 

problem area. Each chapter begins with a brief overview 

of the problem area’s size and characteristics, the main 

countermeasure strategies, a glossary of key terms, and a 

few general references. Next, a table lists specific countermeasures and summarizes their effectiveness, cost, use, 

and implementation time. Each countermeasure then is 

discussed in approximately one page.

The guide provides an overview and starting point for 

readers to become familiar with the behavioral strategies 

and countermeasures in each program area. It focuses on 

countermeasures about which studies have shown evidence 

of effectiveness. Only those countermeasures that are supported by traditional highway safety grant programs have 

been considered. Accordingly, vehicle and roadway-based 

countermeasures are not included. Updates to the guide are 

based only on published research. Unpublished studies and 

research are not included in this edition.

Some countermeasure areas are covered in more depth 

than others, due to the availability of published research. 

For example, impaired driving has a long and rich research 

history, while other topics, such as driver distraction and 

drowsiness, have not been studied as much. This difference 

in the availability of published research findings is due to a 

number of factors, including the relative scale of the problem 

areas, the availability of reliable data on the frequency and 

characteristics of some safety problems, the recency of some 

safety topics, and the challenge of conducting scientifically 

valid studies in certain behavioral areas. 

References are provided for each countermeasure. When 

possible, summaries of available research are included, 

with web links when available, so users can find most of the 

evaluation information in one place. If no summaries are 

available, one or two key studies are cited. There has been 

no attempt to list all research, studies, or program information available on any countermeasure. Readers interested in 

particular problem areas or countermeasures are urged to 

consult the references. Although all web links in this guide 

were accurate at the time of publication, please note that web 

links may change periodically. For broken links to NHTSA 

documents, we recommend searching NHTSA’s behavioral 

safety research reports (https://rosap.ntl.bts.gov). For broken links to other reports or documents, refer to the website 

of the agency that produced the report.

The guide is not intended to be a comprehensive list of countermeasures available for State use or a list of expectations for 

SHSO implementation. For a description of an optimal State 

countermeasure program, Highway Safety Offices should 

refer to the Highway Safety Program Guidelines, which delineate 

the principal components of each of the major program areas.

The evaluations summarized in this guide allow SHSOs to 

benefit from the experience and knowledge gained by others 

and to select countermeasure strategies that have either proven 
2

to be effective or shown promise. States choosing to use innovative programs can contribute to the collective knowledge 

pool by carefully evaluating the effectiveness of their efforts 

and publishing the findings for the benefit of others. 

The Star-Rating System – What the effectiveness data means: 

The effectiveness of any countermeasure can vary immensely 

from State to State or community to community. What is done 

is often less important than how it is done. The best countermeasure may have little effect if it is not implemented vigorously, publicized extensively, and funded satisfactorily. The 

countermeasure effectiveness data presented in the guide probably 

shows the maximum effect that can be realized with high-quality 

implementation. Many countermeasures have not been evaluated well, or at all, as noted in the effectiveness data. Effectiveness ratings (from 1 to 5 stars) are based primarily on 

demonstrated reductions in crashes; however, changes in 

behavior and knowledge are taken into account in the ratings when crash information is not available.

What’s not included: Since the guide is intended as a tool for 

SHSO use, it does not include countermeasures for which 

SHSOs have little or no authority or responsibility, or that 

cannot be supported under typical highway safety grant 

programs. For example, the guide does not include vehicleor roadway-based solutions. Also, it does not include certain 

countermeasures that already are in place in every State, 

such as .08 grams per deciliter blood alcohol concentration 

laws. Finally, because the guide only includes behavioral 

countermeasures and strategies, administrative or management topics such as traffic safety data systems and analyses, 

program planning and assessments, State and community 

task forces, or comprehensive community traffic safety programs are not included. 

What’s new: All chapters of the guide have been revised 

and updated for this biennially published edition. Information and research studies through May 31, 2016, have been 

reviewed and included as appropriate. Data has been updated 

to include information from NHTSA’s 2015 FARS data. 

A significant change in the ninth edition is that the detailed 

descriptions of one- and two-star countermeasures were 

moved to an appendix section in the guide. 

This change is intended to emphasize that counter measures 

that receive one or two stars have NOT been determined to be 

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effective, either because there has been limited or no high quality evidence (one-star), or because effectiveness is still undetermined based on the evidence that is available (two-stars). 

The main section of the guide retains brief summaries for the 

one- and two-star countermeasures to facilitate navigation of 

the topics and to maintain continuity with previous editions.

Although no new chapters have been added to this edition, 

several countermeasures have been expanded:

■ Chapter 1 expands the sections on DWI courts, ignition 

interlocks, DWI offender monitoring, and enforcement of 

drug-impaired driving, and augments the discussion of 

drinking and driving and drug-impaired driving characteristics in the chapter overview.

■ Chapter 2 expands the sections on primary seat belt use 

laws, short-term, high-visibility seat belt enforcement, 

integrated nighttime seat belt enforcement, and inspection stations. 

■ Chapter 3 expands the section on automated enforcement 

and adds to the discussion of strategies to reduce speeding and aggressive driving in the chapter overview. 

■ Chapter 4 expands the sections on graduated driver 

licensing for beginning drivers and high-visibility cell 

phone and text messaging enforcement.

■ Chapter 5 expands the section on motorcycle rider training. 

■ Chapter 7 expands the section on referring older drivers 

to licensing agencies. 

■ Chapter 8 expands the sections on Pedestrian Safe Routes 

to School and enforcement strategies, and adds to the 

crash factors discussion in the chapter overview. 

■ Chapter 9 expands the sections on Bicyclist Safe Routes 

to School, enforcement strategies, and Share the Road 

awareness programs.

How to Order

Download a copy of Countermeasures That Work, Ninth 

Edition from nhtsa.gov. Kristie Johnson, Ph.D., was the task 

order manager for this project.

Suggested APA Citation Format for This Document:

National Highway Traffic Safety Administration. (2018, 

April). Countermeasures That Work, Ninth Edition 

(Traffic Tech Technology Transfer Series. Report No. 

DOT HS 812 479). Washington, DC: Author.

TRAFFIC TECH is a publication to disseminate information 

about traffic safety programs, including evaluations, innovative programs, and new publications. Feel free to copy it as 

you wish. If you would like to to be added to an e-mail list, 

contact TrafficTech@dot.gov.

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