USA Banner

Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Public Roads - January/February 2017

January/February 2017
Issue No:
Vol. 80 No. 4
Publication Number:
Table of Contents

Training Update

Studying Human Behavior to Improve Roadway Safety

by Judy Francis

In 2015, 6.3 million police-reported crashes occurred in the United States. These crashes resulted in 35,092 fatalities and 2.4 million injuries. Although most incidents are attributed to multiple causes, the National Highway Traffic Safety Administration cites human factors as at least one of the contributing causes in approximately 95percent of crash reports.

Addressing human factors in roadway planning and design can help make roadways safer and reduce the likelihood of these factors contributing to injuries and fatalities. To help engineers, planners, and other transportation professionals increase roadway safety, the National Highway Institute (NHI) created course number 380120, Introducing Human Factors in Roadway Design and Operations.

This 2-day instructor-led training offers a thorough introduction to Report 600: Human Factors Guidelines for Road Systems, a National Cooperative Highway Research Program (NCHRP) report focused on road user needs, limitations, and capabilities. The guidelines serve as a resource document for highway designers, traffic engineers, and other safety practitioners by providing objective principles and information on human factors to support and justify design decisions. NCHRP published the first edition of the Human Factors Guidelines in three collections from 2008 to 2010. NCHRP released a second edition in 2012.

Connecting Human Factors and Design

Human Factors Guidelines are user-centered strategies developed to help prevent crashes and fatalities caused by driver behavior, ability limitations, and errors. Transportation professionals must take human factors into account to anticipate potential safety issues and mitigate them through the optimal design and installation of roadways, signs, signals, and markings. Examples of human factors include a road user’s vision, experience, training, cognitive ability, road familiarity, impairment (such as drugs, alcohol, or fatigue), physical abilities (such as reaction time), and expectations.

Participants enrolled in course 380120 review and discuss the guidelines at length and learn how they apply to road system design and operational decisions. Participants leave prepared to design and maintain safer roadways by examining relevant human factors data and principles.

Course 380120 also describes how the Human Factors Guidelines relate to established reference sources such as the Highway Safety Manual, the Manual on Uniform Traffic Control Devices, and the American Association of State Highway and Transportation Officials’ A Policy on Geometric Design of Highways and Streets.


When the Missouri Department of Transportation redesigned the I– 44/Kansas Expressway interchange, as shown here, it extended the medians to reduce the potential for drivers to enter going the wrong way.


Applying the Guidelines

Throughout the course, participants work through various case studies to apply specific human factors guidelines to real roadway situations. For example, a case study examining issues related to human factors at a local complex interchange would include discussion of how the guidelines could be applied at the location, with group members offering ideas and feedback before completing a followup exercise.

The course also uses videos to demonstrate key concepts, as well as exercises to teach participants how to apply the guidelines once they leave the classroom. During the exercises, participants not only identify how a guideline could be used, but also think through the design implications, safety risks, and consequences of ignoring certain information.

“Participants come to class with very diverse educational and professional backgrounds,” says Gabriel Rousseau, safety operations team leader for the Federal Highway Administration. “[They] leave with a better understanding of how individual differences in cognitive and perceptual abilities can impact a road user’s experience. They leave knowing how to apply the guidelines as they design new or retrofit existing roadways, which will help them keep more people safe.”

NHI recommends this course for engineers, planners, and professionals working for State departments of transportation, metropolitan planning organizations, counties, local municipalities, and consultants for other public agencies. Participants will receive 1.2 continuing education units for successfully completing the course.

Human Factors Guidelines and their proper application are a key part of system design and just one part of the toolbox that roadway designers and operations staff can use to improve overall highway safety.

For more information, including pricing and hosting information, visit NHI’s Web site at To register for a session or to sign up to receive email alerts when sessions are scheduled, visit the course description page.

Judy Francis is a contracted marketing analyst for NHI.