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.

NHTSA’s recently published reports are listed chronologically below. To the right are additional resources including Behavioral Research Notes and Traffic Techs.

102 Results
The Effects of Medical Conditions on Driving Performance

This report investigated the effect of selected medical conditions on the exposure and performance of older drivers. Conditions include COPD, age-related macular degeneration, Parkinson’s disease, and peripheral neuropathy. Performance between groups with and without medical conditions was equivalent in virtually all respects based on vehicle kinematic data and crash and near-crash events. A panel discussion sought input from continuing care retirement communities on identifying residents at-risk for driving and overcoming the organizational and personal barriers when residents experience diminished driving performance.

Matching Countermeasures to Driver Types and Speeding Behaviors

This report summarizes a survey of Idaho drivers to learn more about why drivers speed and the countermeasures that might work. The study provides new insights on speeding countermeasures for various driver types and roadway situations and compared survey self-reported speeding citations with actual driver records, providing information on driver recall and self-reporting of driving behavior.

Interlock Data Utilization

This report summarizes findings on ignition interlock data is used for DWI offender monitoring and offender-related programs such as screening, assessments, and treatment for alcohol abuse problems. It describes the uses of interlock data, procedures for using interlock data, and challenges and issues related to using interlock data.

Marijuana-Impaired Driving – A Report to Congress

The report is to educate the public that drugs other than alcohol, including marijuana, are absorbed, distributed and eliminated from the body differently than alcohol. While BAC correlates closely with impairment, there is no such measure (e.g., THC) for marijuana that correlates with impairment. Thus, a BAC-equivalent impairment measure is not possible.

Older-Driver Foot Movements

This study explored how drivers 60 and older control the accelerator and brake while driving and parking, advancing an earlier study about pedal misapplication crashes. An instrumented vehicle on a test route in actual traffic measured foot movement and position affecting possible pedal error. Participants included 6 drivers with peripheral neuropathy of the feet, 2 with hip replacements, and 18 older but healthy drivers. Researchers also documented participants’ functional abilities such as leg functional reach and anthropometries such as height and femur length to determine whether these factors related to pedal control. Drivers with medical conditions scored significantly poorer than the normally aging drivers while parking. Poor vehicle fit was significantly related to functional ability.

Examination of the Feasibility of Alcohol Interlocks for Motorcycles

In 2011 some 30 percent of the 4,612 motorcycle operators involved in fatal crashes had blood alcohol concentrations (BACs) of .08 g/dL or higher. Although alcohol ignition interlocks are a common sanction to deter impaired driving, they are not typically used on motorcycles. This report reviews information on alcohol ignition interlocks to help determine whether they can be an appropriate DUI countermeasure when installed on motorcycles operated by convicted DUI offenders. The report summarizes issues of perceived liability, technical barriers, statutory or legislative barriers, and other factors related to this issue.

Examination of the Legalization and Decriminalization of Marijuana on the DWI System: Highlights from the Expert Panel Meeting

In accordance with the MAP-21 Act, NHTSA and GHSA convened an expert panel to study recreational and/or medical marijuana laws and their effect on driving, including law enforcement, prosecutors, judges, probation, toxicologists, and highway safety officials. The panel identified changes to the DWI system following enactment of laws legalizing and/or decriminalizing marijuana for medical and/or recreational purposes; identified lessons learned; and found measures that should be used to evaluate these laws and their impact on traffic safety and the DWI system.

The Feasibility of Voluntary Ignition Interlocks as a Prevention Strategy for Young Drivers

Young drivers are at greater risk for alcohol-related crash deaths than any other age group, and there has been only limited progress. One innovative possibility that has not yet been tried for most young drivers is the implementation of a voluntary alcohol ignition interlock program as a preventative approach. This study examined its feasibility by discussions conducted in 2010 with ignition interlock manufacturers and service providers, insurance companies, community groups, parents, teens and young adults. Finally, ignition interlock recorder data on users 16 to 26 years old were examined, and a web survey with parents of voluntary users and voluntary users themselves was analyzed.

2013–2014 National Roadside Study of Alcohol and Drug Use by Drivers: Drug Results

This report is one of three that summarizes the results of the 2013–2014 National Roadside Study (NRS) of Alcohol and Drug Use by Drivers. The National Highway Traffic Safety Administration (NHTSA) contracted with the Pacific Institute for Research and Evaluation (PIRE) to conduct this study. This report (Volume 3) presents national prevalence estimates of drug-positive driving and alcohol-plus-drug-positive driving derived from the study, and compares them with the 2007 NRS, which was the first roadside study to estimate the prevalence of drug-positive driving in the Unites States. Another report (Volume 1) describes the sampling plan and data-collection methodology (Kelley-Baker et al., 2016). A third report (Volume 2) (Ramirez et al., 2016) presents the results for alcohol-positive driving.

Determining the Effectiveness Of Flexible Checkpoints

The objectives for this project were to (a) determine how flexible checkpoints are being used in the United States; (b) identify agencies that use flexible checkpoints to document problems or concerns they’ve found, and to determine and document solutions that could be used by other agencies that implement flexible checkpoints; and (c) determine the effectiveness of flexible checkpoints in one site.

For Access to older content please go to our archived Research page.