TRANSPORTATION RESEARCH BOARD 2025 EXECUTIVE COMMITTEE^*

OFFICERS

Chair: Leslie S. Richards, Professor of Practice, University of Pennsylvania, Philadelphia

Vice Chair: Joel M. Jundt, Secretary of Transportation, South Dakota Department of Transportation, Pierre

Executive Director: Victoria Sheehan, Transportation Research Board, Washington, DC

MEMBERS

James F. Albaugh, President and CEO, The Boeing Company (retired), Scottsdale, AZ

Carlos M. Braceras, Executive Director, Utah Department of Transportation, Salt Lake City

Douglas C. Ceva, Vice President, Customer Lead Solutions, Prologis, Inc., Jupiter, FL

Nancy Daubenberger, Commissioner of Transportation, Minnesota Department of Transportation, St. Paul

Marie Therese Dominguez, Commissioner, New York State Department of Transportation, Albany

Garrett Eucalitto, Commissioner, Connecticut Department of Transportation, Newington

Andrew Fremier, Executive Director, Metropolitan Transportation Commission, San Francisco, CA

Martha Grabowski, Professor Emerita, Information Systems, Le Moyne College, Madden College of Business & Economics, Cazenovia, NY

Randell Iwasaki, President and CEO, Iwasaki Consulting Services, Walnut Creek, CA

Carol A. Lewis, Professor, Transportation Studies, Texas Southern University, Houston

Scott C. Marler, Director, Iowa Department of Transportation, Ames

Ricardo Martinez, Adjunct Professor of Emergency Medicine, Emory University School of Medicine, Decatur, GA

Russell McMurry, Commissioner, Georgia Department of Transportation, Atlanta

Craig E. Philip, Research Professor and Director, VECTOR, Department of Civil and Environmental Engineering, Vanderbilt University, Nashville, TN

Steward T.A. Pickett, Distinguished Senior Scientist, Cary Institute of Ecosystem Studies, Millbrook, NY

Susan A. Shaheen, Professor and Co-Director, Transportation Sustainability Research Center, University of California, Berkeley

Marc Williams, Executive Director, Texas Department of Transportation, Austin

EX OFFICIO MEMBERS

Bryan Bedford, Administrator, Federal Aviation Administration, Washington, DC

Michael R. Berube, Deputy Assistant Secretary for Sustainable Transportation, U.S. Department of Energy, Washington, DC

Tariq Bokhari, Acting Administrator, Federal Transit Administration, Washington, DC

Steven G. Bradbury, Deputy Secretary, U.S. Department of Transportation, Washington, DC

Steven Cliff, Executive Officer, California Air Resources Board, Sacramento

Drew Feeley, Acting Administrator, Federal Railroad Administration, Washington, DC

LeRoy Gishi, Chief, Division of Transportation, Bureau of Indian Affairs, U.S. Department of the Interior, Germantown, MD

Firas Ibrahim, Director, Office of Research, Development, and Technology, Office of the Assistant Secretary for Research and Technology (OST-R), Washington, DC

Jason Kelly, Deputy Commanding General for Civil Works and Emergency Operations, U.S. Army Corps of Engineers, Washington, DC

Sandra Knight, President, WaterWonks, LLC, Washington, DC

Ben Kochman, Acting Administrator, Pipeline and Hazardous Materials Safety Administration, Washington, DC

Niloo Parvinashtiani, Engineer, Mobility Consultant Solutions, Iteris Inc., Fairfax, VA, and Chair, TRB Young Members Coordinating Council

Gloria Shepherd, Acting Deputy Administrator, Federal Highway Administration, Washington, DC

Karl Simon, Director, Transportation and Climate Division, U.S. Environmental Protection Agency, Washington, DC

Paul P. Skoutelas, President and CEO, American Public Transportation Association, Washington, DC

Jim Tymon, Executive Director, American Association of State Highway and Transportation Officials, Washington, DC

Sang Yi, Acting Administrator, U.S. Maritime Administration, Washington, DC

_________________________

^*Membership as of August 2025.

NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM

NCHRP RESEARCH REPORT 1152

Leveraging Artificial Intelligence and Big Data to Enhance Safety Analysis

A GUIDE

Yinhai Wang

Shuyi Yin

Mehrdad Nasri

Chenxi Liu

Shucheng Zhang

University of Washington

Seattle, WA

Venky Shankar

Narayan Venkataraman

Rohan Shrestha

Texas Tech University

Lubbock, TX

Brian Chandler

Lacy Brown

Nikki Davis

Houssam Ghandour

DKS Associates, Inc.

Bellevue, WA

Fred Mannering

University of South Florida

Tampa, FL

Janet Gates

Gates Logic

Niwot, CO

Joey Cai

University of California, Berkeley

Berkeley, CA

NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM

Systematic, well-designed, and implementable research is the most effective way to solve many problems facing state department of transportation (DOT) administrators and engineers. Often, highway problems are of local or regional interest and can best be studied by state DOTs individually or in cooperation with their state universities and others. However, the accelerating growth of highway transportation results in increasingly complex problems of wide interest to highway authorities. These problems are best studied through a coordinated program of cooperative research.

Recognizing this need, the leadership of the American Association of State Highway and Transportation Officials (AASHTO) in 1962 initiated an objective national highway research program using modern scientific techniques—the National Cooperative Highway Research Program (NCHRP). NCHRP is supported on a continuing basis by funds from participating member states of AASHTO and receives the full cooperation and support of the Federal Highway Administration (FHWA), United States Department of Transportation.

The Transportation Research Board (TRB) of the National Academies of Sciences, Engineering, and Medicine was requested by AASHTO to administer the research program because of TRBʼs recognized objectivity and understanding of modern research practices. TRB is uniquely suited for this purpose for many reasons: TRB maintains an extensive committee structure from which authorities on any highway transportation subject may be drawn; TRB possesses avenues of communications and cooperation with federal, state, and local governmental agencies, universities, and industry; TRBʼs relationship to the National Academies is an insurance of objectivity; and TRB maintains a full-time staff of specialists in highway transportation matters to bring the findings of research directly to those in a position to use them.

The program is developed on the basis of research needs identified by chief administrators and other staff of the highway and transportation departments, by committees of AASHTO, and by the FHWA. Topics of the highest merit are selected by the AASHTO Special Committee on Research and Innovation (R&I), and each year R&Iʼs recommendations are proposed to the AASHTO Board of Directors, the FHWA, and the National Academies. Research projects to address these topics are defined by NCHRP, and qualified research agencies are selected from submitted proposals. Administration and oversight of research contracts are the responsibilities of NCHRP.

The needs for highway research are many, and NCHRP can make significant contributions to solving highway transportation problems of mutual concern to many responsible groups. The program, however, is intended to complement, rather than to substitute for or duplicate, other highway research programs.

NCHRP RESEARCH REPORT 1152

Project 17-100
ISSN 2572-3766 (Print)
ISSN 2572-3774 (Online)
ISBN 978-0-309-59960-3
Library of Congress Control Number 2025943255

© 2025 by the National Academy of Sciences. National Academies of Sciences, Engineering, and Medicine and the graphical logo are trademarks of the National Academy of Sciences. All rights reserved.

COPYRIGHT INFORMATION

Authors herein are responsible for the originality and accuracy of their materials and for obtaining written permissions from publishers or persons who own the copyright to any previously published or copyrighted material used herein.

The National Academy of Sciences (NAS) grants permission to reproduce written material in this publication for classroom and non-commercial purposes subject to the rights of any third parties and appropriate attribution. Permission is given with the understanding that none of the material will be used to imply NAS, TRB, AASHTO, APTA, FAA, FHWA, FTA, GHSA, or NHTSA endorsement of a particular product, method, or practice. For other uses of the written material, users must request permission from the National Academies Press.

NOTICE

The research report was reviewed by the technical panel and accepted for publication according to procedures established and overseen by the Transportation Research Board and approved by the National Academies of Sciences, Engineering, and Medicine.

This material is based upon work supported by the FHWA under Agreement No. 693JJ32350025. Any opinions, findings, and conclusions or recommendations expressed or implied in this document are those of the researchers who performed the research and are not necessarily those of the Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; the FHWA; or the program sponsors.

The Transportation Research Board does not develop, issue, or publish standards or specifications. The Transportation Research Board manages applied research projects which provide the scientific foundation that may be used by Transportation Research Board sponsors, industry associations, or other organizations as the basis for revised practices, procedures, or specifications.

The Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; and the sponsors of the National Cooperative Highway Research Program do not endorse products or manufacturers. Trade or manufacturersʼ names or logos appear herein solely because they are considered essential to the object of the report.

Published research reports of the

NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM

are available from

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and can be ordered through the Internet by going to

https://nap.nationalacademies.org

The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, nongovernmental institution to advise the nation on issues related to science and technology. Members are elected by their peers for outstanding contributions to research. Dr. Marcia McNutt is president.

The National Academy of Engineering was established in 1964 under the charter of the National Academy of Sciences to bring the practices of engineering to advising the nation. Members are elected by their peers for extraordinary contributions to engineering. Dr. Tsu-Jae Liu is president.

The National Academy of Medicine (formerly the Institute of Medicine) was established in 1970 under the charter of the National Academy of Sciences to advise the nation on medical and health issues. Members are elected by their peers for distinguished contributions to medicine and health. Dr. Victor J. Dzau is president.

The three Academies work together as the National Academies of Sciences, Engineering, and Medicine to provide independent, objective analysis and advice to the nation and conduct other activities to solve complex problems and inform public policy decisions. The National Academies also encourage education and research, recognize outstanding contributions to knowledge, and increase public understanding in matters of science, engineering, and medicine.

Learn more about the National Academies of Sciences, Engineering, and Medicine at www.nationalacademies.org.

The Transportation Research Board is one of seven major program divisions of the National Academies of Sciences, Engineering, and Medicine. The mission of the Transportation Research Board is to mobilize expertise, experience, and knowledge to anticipate and solve complex transportation-related challenges. The Boardʼs varied activities annually engage about 8,500 engineers, scientists, and other transportation researchers and practitioners from the public and private sectors and academia, all of whom contribute their expertise in the public interest. The program is supported by state departments of transportation, federal agencies including the component administrations of the U.S. Department of Transportation, and other organizations and individuals interested in the development of transportation.

Learn more about the Transportation Research Board at www.TRB.org.

COOPERATIVE RESEARCH PROGRAMS

CRP STAFF FOR NCHRP RESEARCH REPORT 1152

Monique R. Evans, Director, Cooperative Research Programs

Waseem Dekelbab, Deputy Director, Cooperative Research Programs, and Manager, National Cooperative Highway Research Program

Roberto Barcena, Senior Program Officer

Zhiye Li, Program Officer

Anthony P. Avery, Senior Program Assistant

Natalie Barnes, Director of Publications

Heather DiAngelis, Associate Director of Publications

Alison Shapiro, Editor

NCHRP PROJECT 17-100 PANEL
Field of Traffic—Area of Safety

John C. Milton, Washington State Department of Transportation, Olympia, WA (Chair)

Majed N. Al-Ghandour, North Carolina State University, Raleigh, NC

Andrew H. Ceifetz, WSP, Walled Lake, MI

Abolfazl Karimpour, State University of New York, Utica, NY

Derek James Leuer, Minnesota Department of Transportation, Roseville, MN

Inya Nlenanya, Iowa State University, Ames, IA

Mohamadreza Banihashemi, FHWA Liaison

Kelly K. Hardy, AASHTO Liaison

FOREWORD

By Roberto Barcena
Staff Officer
Transportation Research Board

NCHRP Research Report 1152: Leveraging Artificial Intelligence and Big Data to Enhance Safety Analysis: A Guide presents a process to advance the use of artificial intelligence (AI) and big data to enhance safety analyses. The process also includes strategies to apply machine learning (ML) and other tools to develop algorithms to support data-driven safety decisions and outcomes. The guide was developed and supported with information gathered during the implementation of pilot projects focused on safety analyses.

This research report will be of immediate interest to roadway safety and information technology personnel in state and local transportation agencies. The report will be a resource to inform their decisions related to the use of AI, ML, and big data in safety and other applications.

The need to improve road safety performance for all users is important for state departments of transportation and other transportation agencies. At the same time, the optimization of investments by these agencies to save lives and reduce injuries takes on even greater importance when financial resources are constrained. The use of sensors, available data, software applications, and innovative safety performance analyses can help agencies achieve safer roads for all users through targeted investments.

Under NCHRP Project 17-100, “Leveraging Artificial Intelligence and Big Data to Enhance Safety Analysis,” the University of Washington was asked to advance the use of AI and ML for analyzing big data and unconventional data and to assess the effectiveness of these tools for supporting safe system and modal priority decision-making.

In addition to NCHRP Research Report 1152, the project produced several deliverables that are not included in the published report but can be found on the National Academies Press website (nap.nationalacademies.org) by searching for NCHRP Research Report 1152: Leveraging Artificial Intelligence and Big Data to Enhance Safety Analysis: A Guide. The deliverables are as follows:

• Conduct of Research Report
• Case Studies
  • Case Study 1: Inventorying Streetlight Luminaires (Oregon DOT)
  • Case Study 2: Analysis of Vehicle Turning Behavior (City of Bellevue)
• Presentations with AI and Big Data Safety Applications
  • Classified Vehicle Volume Using Loop Detector Data
  • Counting Turning Movements Using Connected Vehicle Data
  • Lane Markings and Width Using LiDAR Data
  • Traffic Sign Detection and Recognition Using Road Log Videos
  • Vulnerable Road User Detection Using Computer Vision
  • Detection of Weather-Related Road Surface Conditions

CONTENTS

Chapter 1 Introduction

Intended Audience

Importance of Transportation Safety

Project Purpose and Overview

Definitions and Descriptions

User Guide Organization

Chapter 2 Traditional Safety Evaluations

Overview of Traditional Safety Evaluations

Traditional Datasets

Traditional Analysis Techniques

When to Consider Advanced AI/ML Tools for Analysis

Chapter 3 How AI, ML, and Big Data Can Improve Safety Evaluations

New and Enhanced Datasets

Advanced Analysis Methods

Steps to Prepare Data for ML Analysis

Examples of Data Sources to Be Used in iRAP Roadway Safety Assessment

Introduction to Example AI/ML Methods and Applications

Chapter 4 Applying AI, ML, and Big Data to Safety Analysis

Case Study #1: Capturing New Data with ML, ODOT

Case Study #2: Analyzing Big Data, Bellevue, Washington

Chapter 5 Additional AI, ML, and Big Data Applications

Introduction

Python Primer

Classified Vehicle Volume Using Loop Detector Data

Turning Movement Counts Using CVD

Lane Markings and Width Using LiDAR Data

Traffic Sign Detection and Recognition Using Road Log Videos

Pedestrian Detection Using Mounted Surveillance Cameras

Road Surface Condition Detection Using Edge Devices

References and Bibliography

Abbreviations and Acronyms