The Safety Impact of Road Debris: Updated Prevalences of Crashes, Injuries, and Deaths in the United States, 2018–2023

Abstract

Introduction

Road debris presents a significant threat to traffic safety. It can contribute to crashes directly when vehicles are struck by objects actively falling or strike debris lying on the road. It can also contribute to crashes indirectly, when drivers crash while performing sudden evasive maneuvers to attempt to avoid debris. However, research on the danger posed by road debris is limited, due to limitations in how road debris is recorded in national crash databases. The purpose of this research was to estimate the number of crashes, injuries, and deaths attributable to road debris in the United States, and to examine the nature and likely sources of debris to inform potential countermeasures.

Methodology

To estimate the national prevalence of crashes involving road debris from 2018 – 2023, the study employed a two-stage approach integrating in-depth review of police crash reports with national-level crash data.

First, 901 police reports from crashes in the state of Michigan were reviewed in depth to determine the frequency of actual debris involvement in crashes with general characteristics suggestive of possible debris involvement. These included crashes in which a vehicle struck or was struck by a non-fixed object or crashed while attempting to avoid such an object. The research team reviewed officer narratives and scene diagrams to determine whether each crash actually involved road debris.

Next, national crash databases compiled by the United States Department of Transportation were used to determine the total number of crashes with characteristics suggestive of possible debris involvement. The results of the in-depth review of Michigan police crash reports were then used in conjunction with these national statistics to estimate how many crashes nationwide were likely to have actually involved road debris. The study also analyzed the types and likely sources of debris to identify common hazards and inform the development of targeted safety countermeasures.

Results

Findings indicate that road debris was a factor in an estimated 319,724 motor vehicle crashes, 32,802 injuries, and 433 fatalities in the United States between 2018 and 2023, averaging approximately 53,000 crashes, 5,500 injuries, and 72 deaths annually.

The most common sources of debris identified in crashes included vehicle parts that had detached from other vehicles; miscellaneous cargo, tools, and building materials; as well as natural debris such as tree branches and roadkill.

Among crashes with general characteristics suggestive of possible debris involvement, debris was more likely to be confirmed as a factor in lower-severity crashes than in fatal or serious injury crashes. Among debris-related crashes, those in which the driver crashed after attempting to avoid the debris tended to be more severe than crashes in which the vehicle struck or was struck by debris.

Findings from this research highlight road debris as a significant but understudied factor in traffic crashes, injuries, and fatalities across the United States. The majority of crashes examined in this study involved debris originating from other vehicles, followed by vehicle cargo, commonly furniture, sporting equipment, and other miscellaneous objects.

A coordinated effort is needed to address road debris as a safety issue. National and state agencies should implement countermeasures, such as standardized crash documentation, prioritized debris removal, and consistent enforcement of laws regarding load securement. Drivers can also help reduce debris-related crash risks by securing their cargo, maintaining their vehicles, and adopting defensive driving techniques.

This Research Brief provides additional data and insights on the role of road debris in traffic crashes and what can be done to mitigate it.