Research & Evaluation
Behavioral Research
Behaviors and Attitudes
NHTSA studies behaviors and attitudes in highway safety, focusing on drivers, passengers, pedestrians, and motorcyclists. We identify and measure behaviors involved in crashes or associated with injuries, and develop and refine countermeasures to deter unsafe behaviors and promote safe alternatives.
Our recently published reports and research notes are listed chronologically below. To the right are additional resources including Traffic Techs.
| Title | |
|---|---|
Drug Testing and Traffic Safety: What You Need to KnowDrugged driving is both of great interest and very complex. This report continues that discussion by examining how drug use data from people involved in a motor vehicle crashes is entered into NHTSA’s Fatality Analysis Reporting System (FARS), a cornerstone of NHTSA's information collection systems. It has given Federal and State agencies, legislators, advocacy groups, and researchers key data about fatal motor vehicle crashes for all road user types and on all public roads. It is internationally respected for its breadth and depth of data. But reporting drug use across a myriad of substances, and with varying testing protocols across forensic laboratories and across States can lead to confusion about the meaning of results. Currently, the limitations described in this report constrain interpretation of drug test results data, including comparisons across jurisdictions or years. In some other research areas with missing or incomplete data, estimates may still be useful. This is not the case with FARS drug data. The report discusses NHTSA’s actions for improving the quantity and quality of drug data in FARS. |
DOT HS 813 264 |
Characteristics of State Law Enforcement Liaison ProgramsThis study increased understanding of State law enforcement liaison (LEL) programs by describing their characteristics, duties, responsibilities, and activities. It included an online survey of LELs and their State Highway Safety Office (SHSO) program managers to identify program characteristics and practices. A total of 105 LELs and 31 SHSO representatives completed the surveys. Nearly 75% of the LELs responded that they were directly accountable to their SHSOs. Over 75% of the LELs focused on impaired driving, occupant protection, distracted driving, and speed management. Specific LEL characteristics, such as superior communication and interpersonal skills, knowledge of State traffic safety laws and general police methods, connections with LEAs, and high energy and charisma were identified as important factors for a productive program. |
DOT HS 813 259 |
A How-to Guide for Conducting a Statewide Roadside Survey of Alcohol and Other DrugsThis guide details the steps for a State to conduct its own statewide roadside survey of the prevalence of alcohol and other drug use among drivers, important components of addressing impaired driving. NHTSA has conducted several voluntary and anonymous National Roadside Surveys. NHTSA and also worked with the State of Washington State to conduct a statewide survey before and after legalization of the recreational use of cannabis in that State. If a State is interested in conducting its own statewide roadside survey, this guide draws on these past experiences to provide start-to-finish guidance on how to develop and implement a statewide survey of alcohol and other drug prevalence among drivers. The guide includes information on how to develop a study plan, budget, and conduct specimen collection, research questions that can be addressed, personnel and equipment needed, and issues that may arise. |
DOT HS 813 198 |
Evaluating High Visibility Enforcement of Bicycle Passing LawsThis study selected Grand Rapids, Michigan, and Knoxville, Tennessee, to implement high-visibility enforcement (HVE) programs to increase compliance with laws requiring drivers to leave a minimum distance when passing a bicycles. In Grand Rapids, a local ordinance required leaving 5 feet, and in Knoxville the State law and local ordinance required a minimum 3 feet to pass. Police in both cities used the same ultrasonic measuring devices to determine if drivers passing decoy officers on a bicycles were too close. Each city developed its own publicity program to increase the visibility of the enforcement. HVE programs continued for approximately 4 months in each city. Results showed that the average passing distance in both cities during baseline was already well in excess of the prevailing legal requirement, but violations were still high. By the end of the HVE programs, statistically significant increases in average passing distance and significant decreases in violations were achieved in both cities. |
DOT HS 813 248 |
Evaluation of Utah’s .05 BAC Per Se LawOn December 30, 2018, Utah became the first State to lower their legal driving limit from .08 to .05 g/dL. This research report is an evaluation of the impacts of this lower limit. |
DOT HS 813 233 |
Detecting Change in Community Traffic Safety AttitudesHistorically, evaluations of community traffic safety programs have collected data using nonprobability intercept surveys rather than more rigorous probability surveys, or they used secondary data instead of primary data collection of any kind. However, it is not always feasible to use probability sampling when collecting data based on operational complexity, statistical complexity, cost, and timing constraints. This report may help build on basic statistics knowledge of community traffic safety program evaluators by highlighting sound practices for using nonprobability sampling methods and secondary data sources using opt-in online panel surveys with quota sampling and intercept surveys with quota sampling. |
DOT HS 813 242 |
Older Driver Performance Across Six Naturalistic StudiesThis study aggregated and analyzed naturalistic data from six NHTSA-sponsored studies to determine the extent older drivers’ scores on clinical measures were associated with ability to control their vehicles, including traffic control devices and maintaining proper lane position. Researchers also examined the association between the clinical measures and indices of driving exposure (total mileage and total driving time, exposure to high-speed and limited-access roadways, and other situations). Analyses of NHTSA on-road performance and naturalistic driving data explored whether participants with poorer driving skills were more likely to limit their overall driving (time or miles), avoid difficult conditions, or otherwise self-regulate. Researchers used the SHRP2 Naturalistic Driving Study, yielded findings suggesting significant differences in driver responses in crash and near-crash events tied to measures of both cognitive and physical function. |
DOT HS 813 181 |
Continuation of Research on Traffic Safety During the COVID-19 Public Health Emergency: January - June 2021, Research NoteAfter the declaration of the COVID-19 public health emergency in March 2020, American driving patterns and behaviors changed significantly. Of drivers who remained on the roads, some engaged in riskier behavior -- speeding, failure to wear seat belts, driving under the influence of alcohol or other drugs. Data showed average speeds increased 20 miles per hour or more, higher than the posted speed limit, and an estimated 11 percent increase in speeding-related fatalities. Other data suggested fewer people in crashes used their seat belts. Earlier research reports showed changes in the prevalence of alcohol and other drugs during the pandemic among seriously or fatally injured road users at different phases of the pandemic. |
DOT HS 813 210 |
Exploring the Relationship between Entry-Level Motorcycle Rider Training and Motorcycle CrashesResearch on entry-level motorcycle rider training has not supported the effectiveness or ineffectiveness of training and the relationship between entry-level motorcycle rider training and motorcyclist safety has not been thoroughly explored. This study explored the relationship between entry-level motorcyclist training and safety-related outcomes: (1) Do crash characteristics like collision type, contributing factors, etc., differ between trained and untrained riders? (2) Is there a difference in rider behavior (speed, impairment, or aggressive driving) between trained and untrained riders? (3) What types of citations were issued to trained and untrained riders operating motorcycles or passenger vehicles? (4) Do crash injury severity and type differ between trained and untrained riders? To address these questions, analysis of public records linking motorcyclists’ training to crash data, citation data, and hospital records was carried out using Maryland’s Crash Outcome Data Evaluation System. |
DOT HS 813 189 |
Activity Level, Performance, and Exposure Among Older DriversThis project explored the relationship between the fitness of older people – operationalized through multiple measures of physical activity level and cognitive status – and their driving performance and exposure. While higher physical activity levels generally were associated with better road test performance, in all cases relationships were very weak, accounting for less than 3% of the variance in the performance evaluations. |
DOT HS 812 734 |