National Driver Register
NHTSA Crash Tests
Computing a BAC Estimate
DWI Detection Guide
DWI Detection at BACs below 0.10
The Effects of 0.08 BAC Laws
FARS--Fatal Accident Reporting System
A Review of the Literature on the Effects of Low Doses of Alcohol on Driving-Related Shills

National Highway Traffic Safety Administration, U. S. Department of Transportation was established by the Highway Safety Act of 1970, as the successor to the National Highway Safety Bureau, to carry out safety programs under the National Traffic and Motor Vehicle Safety Act of 1966 and the Highway Safety Act of 1966. It implements consumer programs established by the Motor Vehicle Information and Cost Savings Act, enacted in 1972.

NHTSA is responsible for reducing deaths, injuries and economic losses resulting from motor vehicle crashes. They set and enforce safety performance standards for motor vehicle equipment, and through grants to state and local governments enable them to conduct effective local highway safety programs. The NHTSA has targeted reducing the drunk driving death toll to 11,000 by 2005 in all 50 states and the District of Columbia.

NHTSA investigates safety defects in motor vehicles, sets and enforces fuel economy standards, helps states and local communities reduce the threat of drunk drivers, promotes the use of safety belts, child safety seats and air bags, investigates odometer fraud, establishes and enforces vehicle antitheft regulations and provides consumer information on motor vehicle safety topics.

NHTSA conducts research on driver behavior and traffic safety, to develop efficient and effective means of bringing about safety improvements.

A toll-free Auto Safety Hotline provides recall information, receives motor vehicle SAFETY complaints and furnishes consumers with a wide range of information on auto safety. The Hotline operates from 8 am to 10 p.m. Eastern Time, Monday thru Friday. Calls may be received during nonbusiness hours by means of an automated telephone answering service. A Spanish speaking operator is available from 8 a.m. to 4 p.m. http://www.nhtsa.dot.gov/

Alcohol and highway safety 2001: a review of the state of knowledge, Includes alcohol impaired crashes by state http://www.nhtsa.dot.gov/people/injury/research/AlcoholHighway/

Alcohol-Impaired Driving December 2014

U. S. DOT Releases 2009 State-by-State Data on Alcohol-Related Traffic Fatalities; Statistics Underscore Drunk Driving is Deadliest of Crimes

"Computing a BAC Estimate" summary: The amount of alcohol is usually referred to as BAC -- blood alcohol concentration -- although it is often measured in the breath where the alcohol level in the water vapor of the breath follows the alcohol level in the blood, .012 per hour decline, updated 11-02-98
Search tip: Use Google to search "Computing a BAC Estimate" you should locate the PDF for this document to be downloaded, saved and printed.

Driver Characteristics at Various BACs 2000

DWI Detection Guide
For the "Visual Detection of DWI Motorists" brochure, the researchers interviewed officers through out the United States to develop a list of more than 100 driving cues that predict blood alcohol concentrations above .08 percent. The list was reduced to 24 cues involving three field studies involving hundreds of officers and more than 12,000 enforcement stops. These are the major subject areas:
Problems Maintaining Proper Lane Position
Speed and Braking Problems
Vigilance Problems
Judgment Problems

DWI Detection at BACs below 0.10 NHTSA has sponsored a number of research projects during the past twenty years to improve law enforcement officers ability to detect drivers and motorcyclists whose driving/riding is impaired by alcohol. Visual cues that were good predictors of DWI were identified and training materials for law enforcement use were developed. When those projects were undertaken, the legal limit for alcohol was 0.10 in most jurisdictions. Now that many states have lowered the legal BAC limit to 0.08, and many others have passed zero-tolerance laws for youth under 21, there is a need to identify driving cues that predict DWI at BACs below 0.10. A technical report describing this research is available, as well as training materials for police use. The Visual Detection of DWI Motorists is a brochure with accompanying training video for law enforcement to identify DWI motorists at BACs below 0.10.

Stuster, Jack W,. "The detection of DWI at BACs below 0.10", NHTSA., September, 1997. The objective of the research described in this report has been to develop training materials to assist law enforcement officers in the accurate detection of motorists who are driving while impaired (DWI) at the 0.08 BAC level. The project was composed of 13 major project tasks, conducted in two phases. During Phase I, a work plan was developed to guide all subsequent tasks, a comprehensive review of the low BAC literature was performed, interviews were conducted with DWI experts from across the United States, a data base of low BAC arrest reports was assembled, and two field studies were conducted (the ride-along and preliminary field studies). The analysis of archival, interview, arrest reports, and field data collected by observers led to the identification of 34 driving cues and 10 post-stop cues for further evaluation.

Five law enforcement agencies participated in the second of the field studies, knows as the preliminary field study, by recording the driving and post-stop cues observed for all enforcement stops, regardless of the disposition of the stop; the BACs of all drivers who exhibited objective signs of having consumed alcohol also were recorded. By collecting data about all enforcement stops that were made, it was possible to calculate the proportions of the stops in which specific cues were found in association with various BAC levels. All archival, interview, and field study data were analyzed, and recommendations for draft during materials were developed, as the final Phase I task.

A draft DWI detection guide, training booklet, and training video were developed based on the results of the preliminary field study; the materials included 24 driving and 10 post-stop cues. Law enforcement agencies representing 11 of the 15 states with 0.08 BAC limits for DWI were recruited to participate in the Phase II validation study. Participating officers reviewed the video and printed training materials, then completed a data collection in the preliminary field study, conducted previously. The validation study data were analyzed and a final version of the training materials, and the technical report, were prepared as the final Phase II project tasks.

The results of the preliminary field study largely supported the 20 cues on the original NHTSA (0.10) DWI detection guide at the 0.08 BAC level, but found no cues that reliable predicted BACs below 0.08. The results of the Phase II validation study further confirmed the key cues that were contained in the original NHTSA guide, a few additional driving cues, and the 10 post-stop cues. The driving cues were presented in functional categories in both the printed materials and the training video: Problems Maintaining Proper Lane Position, Speed and Braking Problems, Vigilance Problems, and Judgment Problems.

Apsler, Robert; Char, A. R.; Harding, Wayne M.; Klein, Terry M.; The Effects of 0.08 BAC Laws, National Highway Traffic Safety Administration, March 1999. Straightforward and powerful reasons exist for lowering the legal limit of blood alcohol concentration (BAC) from 0.10 to 0.08. In 1964, Borkenstein et al. showed that drivers who had been drinking were more likely to be involved in a crash than sober drivers, and that beginning with low BACs, the greater the level of intoxication, the higher the probability of being in a crash. Other investigators have replicated and refined Borkenstein et al.'s original findings. More recently, Mounce and Pendleton (1992) extended this line of research by showing that driver BAC is associated with the probability o being responsible for a crash in which they were involved. Research also shows that virtually all drivers, even experienced drivers, are significantly impaired with regard to critical driving tasks at 0.08 BAC. The strong relationship between BAC level, probability of crash involvement, and increase impairment, has led a growing number of states to lower their legal BAC limits. To date, 16 states and the District of Columbia have lowered the BAC limit to 0.08 for adult drivers.

Impaired Driving Impaired Driving research

  • Recent research on impaired driving arrests
  • The ABCs of BAC
  • Survey of DWI Courts
  • Evaluation of state Ignition Interlock Programs
  • Roadside Survey of Alcohol and Drug Use
  • Drug and Alcohol Crash Risk

NHTSA Crash Tests Each year, as part of the New Car Assessment Program (NCAP), the government buys brand new cars right off the lots and crashes them. Why? To compare how well different vehicles protect front-seat passengers in a head-on collision. Results are given in a one-to-five star rating, with five stars indicating the most protection, and one star, the least.

Federal law requires all passenger cars to pass a 30 mph frontal crash test. NCAP tests are conducted at 35 mph to make the differences between vehicles more apparent. The tests are equivalent to a vehicle moving at 70 mph striking an identical parked vehicle.

During the test, instrumented dummies wearing safety belts measure the force of impact to the chest, head, and leg. These readings are the basis of the star rating. Reminder: Crash test ratings are only meaningful when comparing vehicles in the same weight class. Search the NHTSA Database for crash test results on the following:

  • Cars
  • Trucks
  • Vans
  • SUVs
  • Airbags


NHTSA Releases Two New Studies on Impaired Driving on U. S. Roads
Results of the. 2013-2014 National Roadside Survey of Alcohol and Drug Use by Drivers and Drug and Alcohol CrashRisk

"A Review of the Literature on the Effects of Low Doses of Alcohol on Driving-Related Skills", Herbert Moskowitz, Dary Fiorentin, April 2000, FINAL REPORT. 112 research reports reviewed. Contents: Overall Impairment. Impairment, by Behavioral Areas, Driving and Flying: On the Road and Simulators, Divided Attention, Drowsiness, Vigilance Tasks, Tracking, Perception, Visual Functions, Cognitive Tasks, Psychomotor Skills, Choice Reaction Time, Simple Reaction Time, Critical Flicker Fusion, and Aftereffects.

"Statistical watch: change in drunk driving terminology questioned", IMPAIRED DRIVING UPDATE (Summer, 2010), page 68. "NHTSA revised the deviations of an alcohol-related fatal crash in 2007. While any involvement with alcohol (i.e., alcohol impaired) used to qualify, NHTSA now maintains that one of the drivers must be legally intoxicated with a BAC of 0.08% or above. So, instead of some 17,000 fatalities in 2007, as there would have been under the old definition, NHTSA reported only 12,998. This is misleading because alcohol impairment can occur for some individuals after just one drink, and for most, after two. The actual death toll of alcohol-related fatalities was 15,438 in 2008; NTHSA did not include the 3,665 innocent people who were killed by alcohol involvement drivers with a BAC of under 0.08%.

Traffic Safety Facts 1992-2016: see State Alcohol Estimates and State Alcohol-impaired Driving Estimates


updated 12/21/16