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. The most recent Behavioral Research Note is dated October 2017. The most recent Traffic Tech is dated September 2017.
National Traffic Speeds Survey III: 2015
A field survey was conducted during the summer of 2015 as a longitudinal repetition to similar efforts undertaken in 2007 and 2009. 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. Over 12 million vehicle speeds were measured at 677 sites included in the geographic cluster sample of 24 primary sampling units (PSUs). Each PSU was a county, or group of two or three counties representing combinations of regions of the United States, level of urbanization, and type of topography (flat, hilly, mountainous). Speeds were acquired on randomly drawn road segments on limited access highways, major and minor arterial roads, and collector roads. Speed measurement sites were selected in road segments with low, medium, or high degrees of horizontal and vertical curvature or gradient.
National Survey on Distracted Driving Attitudes and Behaviors – 2015
The 2015 National Survey on Distracted Driving Attitudes and Behaviors (NSDDAB) is the third in a series of telephone surveys on distracted driving providing data to help further the understanding of driving behavior and to contribute to the development of countermeasures and interventions to reduce distracted driving on the nation’s roadways. Specifically, the 2015 NSDDAB assessed the extent to which drivers are distracted by various activities; demographic and typological descriptions of drivers prone to distractions; the extent and frequency of cell phone use, texting, and use of mobile device “apps” while driving; attitudes and perceptions about distracted driving; knowledge of and attitudes toward measures to deter distracted driving; perceptions about the danger of distracted driving; exposure to the consequences of distracted driving; willingness to intervene when someone is distracted while driving; and changes and trends in distracted driving behaviors and attitudes since 2010. Like the previous studies conducted in 2010 and 2012, this survey yields national estimates of behaviors and attitudes toward distracted driving in the United States. The present study used a driver typology based on the pattern of responses across multiple distracted driving behavior questions. The cluster analysis identified two distinct groups of drivers with similar overall behavioral tendencies and, among those categorized, 42% are distraction-prone and 58% are distraction-averse. Driver type is a powerful predictor of norms and attitudes towards distracted driving behavior and sanctions for distracted driving.
National Telephone Survey on Distracted Driving Attitudes and Behaviors – 2015
National telephone survey of distracted driving to monitor the public’s attitudes, knowledge, and self-reported behavior about cell phone use and texting while driving, and driver choices.
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.
For Access to older content please go to our archived Research page.