Research & Evaluation

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.

Latest Reports

Teen Driver Safety: Review of the Literature on Driver Education Evaluation (2010 Update)
This report is part of the Large-scale Evaluation of Driver Education Project being conducted by the Traffic Injury Research Foundation and Northport Associates for the AAA Foundation for Traffic Safety. The study is sponsored by the AAA Foundation for Traffic Safety; National Highway Traffic Safety Administration; Centers for Disease Control, National Center for Injury Prevention and Control; and Manitoba Public Insurance.
Motivations for Speeding, Volume I: Summary Report
This is Volume I of a three-volume report. It contains the results of a study that examined the speeding behavior of drivers in their own vehicles over the course of three to four weeks of naturalistic driving in urban (Seattle, Washington) and rural (College Station, Texas) settings.
Impact of Implementing a Primary Enforcement Seat Belt Law in Florida: A Case Study
This study examined the changes in belt usage associated with the primary law change and the contribution of the rural and statewide belt programs. Awareness surveys indicated that 94% of respondents knew of the primary law and 77% supported the law immediately after the law went into effect.

National Traffic Speeds Survey I: 2007
A field survey was conducted during Spring and Summer 2007 to measure travel speeds and prepare nationally representative speed estimates for all types of motor vehicles on freeways, arterial highways, and collector roads across the United States.
National Travel Speeds Survey II: 2009
A field survey was conducted during spring and summer 2009 as a longitudinal repetition to a similar effort undertaken in 2007. The goal was to measure travel speeds and prepare nationally representative speed estimates for all types of motor vehicles on freeways, arterial highways, and collector roads across the United States.
Functional Assessments, Safety Outcomes, and Driving Exposure Measures for Older Drivers
This project was conducted to provide an objective measure of the relationship between older adults' scores on a set of driving assessment tools and their (serious point) violations and crashes over a period of 18 months following the assessments. An additional objective was to compare alternative methods of measuring driver exposure.
Breath Test Refusals and Their Effect on DWI Prosecutions
This report describes the design and results of a project aimed at estimating the rate that drivers refuse to submit to a legally-requested breath alcohol concentration test, and the effect of such refusals on the prosecution of DWI cases. The study found the mean refusal rate to be 21% in 39 jurisdictions providing data, a very small change from that found in prior studies. The study did not indicate a clear relationship between refusing a BAC test and the probability of conviction for DWI/DUI across five local study sites.
Demonstration and Evaluation of the Heed the Speed Pedestrian Safety Program
This study built upon the work of Blomberg and Cleven (2006) in Arizona, where they developed and pilot-tested the concept of Heed the Speed, a neighborhood-based combination of enforcement, education, and modest engineering designed to reduce vehicle speeds to benefit pedestrian safety. The current program was expanded and applied to Philadelphia, Pennsylvania, in an attempt to determine if reducing speeds in neighborhoods would lead to a reduction in pedestrian-involved crashes.
Review of Studies on Pedestrian and Bicyclist Safety, 1991-2007
This report reviews the pedestrian and bicyclist safety research literature in print as of 2007. It summarizes and synthesizes the key studies, evaluates existing knowledge and identifies research gaps and provides recommendations for future direction.
A Fresh Look at Driver Education in America
The objectives of this study were to: (1) identify and review current driver education and training programs in use nationally and internationally; (2) identify best teaching practices for teenagers; (3) examine the optimal sequencing for the presentation of safe driving skills in the classroom and behind-the-wheel training; and (4) assess whether a new approach to driver education would be beneficial.
Examination of Supplemental Driver Training and Online Basic Driver Education
This report describes supplemental driver training programs and online basic driver education. It coves supplemental driver training that focused on knowledge and skills beyond those normally found in traditional driver education delivered in the United States and in other countries. It also reviewed online basic driver education programs that were approved in at least one U.S. State to replace the standard driver education classroom requirement in the driver licensing process.
The Effect of Passengers on Teen Driver Behavior
Risky driving behaviors by teenage drivers were more common while they were driving in the presence of teenage peers. Teenage drivers were two-and-a-half times more likely to engage in one or more potentially risky behaviors when driving with one teenage peer compared to when driving alone. When driving with multiple teenage peers the likelihood increased to 3 times.
Research Note: Young Drivers Report the Highest Level of Phone Involvement in Crash or Near-crash Incidences.
This research note extracts information from the December 2011 telephone survey about cell phone use and distracted driving for young drivers. Young drivers report more crashes while using cell phones. Most drivers report that using a cell phone while driving makes no difference on their driving but texting or emailing does.
Role of Supervised Driving Requirements in Graduated Driver Licensing Programs
Many States require parents to certify that their teens have completed a certain amount of supervised driving practice, usually 40 to 50 hours, before they are permitted to obtain an intermediate license. Although strongly supported by numerous groups and organizations, the effectiveness of supervised practice requirements is unknown. NHTSA conducted a cross-sectional comparison of fatal crash rates throughout the United States, and examined State crash data using interrupted time-series analysis in a small number of States that had increased their required number of supervised driving hours.
Pedal Application Errors
This project examined the prevalence of pedal application errors and the driver, vehicle, roadway and/or environmental characteristics associated with pedal misapplication crashes based on a literature review, analysis of news media reports, a panel of driver rehabilitation specialists, analysis of multiple crash databases, and case studies. An analysis of crashes attributed to pedal-related vehicle equipment malfunction, rather than to a driver error, was also carried out based on a media scan.
Taxonomy of Older Driver Behaviors and Crash Risk
This study updates and extends our understanding of how age-related functional deficits can influence driver performance, and in turn crash risk for older drivers. It also examines the potential for behavioral countermeasures targeted to the remediation or accommodation of such deficits to attenuate critical errors in performance, and thus to reduce crash risk. A taxonomy table displaying the demonstrated and inferred links between these variables was developed as the central product of this research.
National Phone Survey on Distracted Driving Attitudes and Behaviors
Most drivers will answer a call while driving and most will continue to drive after answering. About 2 out of 10 drivers (18%) report that they have sent text messages or e-mails while driving; about half (49%) of those 21 to 24 years old report doing so. More than half believe that using a cell phone and or sending a text message/e-mail makes no difference on their driving performance, yet as passengers, 90% said they would feel very unsafe if their driver was talking on a handheld cell phone or texting/e-mailing while traveling with them.
Evaluation of Teen Seat Belt Demonstration Projects in Colorado and Nevada
Teen seat belt use increased significantly in both States. Overall gains of 5 percentage points in Colorado and 8 points in Nevada were substantial, particularly given that both States have secondary enforcement laws and low fine levels ($20 in Colorado; $25 in Nevada).
Public Awareness Survey Recommendations of the NHTSA-GHSA Working Group
The Governors Highway Safety Association (GHSA) and the National Highway Traffic Safety Administration (NHTSA) developed a basic set of survey questions including information on seat belt use, impaired driving, and speeding. These core questions can be used in regular telephone or similar surveys to track driver attitudes and awareness of highway safety enforcement and communication activities and self-reported driving behavior. This working paper summarizes the results.
Determining the Relationship of Primary Seat Belt Laws to Minority Ticketing
This study found that primary laws were related to gains in seat belt use without evidence of racial profiling associated with changing the law from secondary to primary.
Documenting How States Recently Upgraded to Primary Seat Belt Laws
This study documented the roles, strategies, resources, and arguments these States used in efforts to pass primary belt laws.
Pilot Study of Instrumentation to Collect Behavioral Data to Identify On-Road Rider Behaviors
Motorcycle-related research questions of interest to NHTSA were reviewed. Instrumentation techniques and study procedures that have been used for light- and heavy-vehicle studies were adapted for use in answering the motorcycle-related questions. Analyses were conducted to illustrate possible uses of the data and to confirm the effectiveness of the adapted instrumentation.
Field and Simulator Evaluations of a PC-Based Attention Maintenance Training Program
This report presents the results of three research studies regarding driver distraction from the forward roadway due to secondary in-vehicle tasks. Together, the results from these three studies suggest that young drivers may benefit from training that addresses attention maintenance skills.
Medical Review Process and License Disposition of Drivers Referred by Law Enforcement and Other Sources in Virginia
This report describes the medical review process and license outcomes for 100 drivers referred by law enforcement officers in Virginia. Additionally, it describes the license outcomes for 105 drivers referred by seven other sources: the courts for people adjudicated as mentally incapacitated, general traffic court, customers who self-report medical conditions on license application and renewal forms, DMV customer service representatives, the Department for the Blind and Vision Impaired (DBVI), family members, and physicians.
Evaluation of the DUI Court Program in Maricopa County, Arizona
This is the final report of a project that evaluated the effectiveness of a DUI court program aimed at reducing felony DUI offenders’ subsequent alcohol-related traffic violations.
Four High-Visibility Enforcement Demonstration Waves in Connecticut and New York Reduce Hand-Held Phone Use
Drivers using hand-held cell phones while driving dropped 57% in Hartford (from 6.8% to 2.9%) and 32% in Syracuse (from 3.7% to 2.5%). Drivers who were texting while driving declined 72% in Hartford (from 3.9% to 1.1%) and 32% in Syracuse (from 2.8% to 1.9%).