Safety Report on Eliminating Impaired Driving

 

Frequently ASked Questions

Why has the NTSB issued this report?

Most Americans think we have solved our nation's drunk driving problem. We haven't come close. Impaired driving is a national epidemic. Every hour, one person is killed and 20 people are injured in crashes involving an alcohol-impaired driver. That adds up quickly to nearly 10,000 deaths and more than 173,000 injuries each year.

The recommendations in this report represent the culmination of a year-long NTSB effort focused on the problem of substance-impaired driving. In May 2012, the NTSB held a forum, "Reaching Zero: Actions to Eliminate Substance-Impaired Driving," to identify the most effective, scientifically based actions needed to reach zero crashes associated with substance-impaired driving. In November 2012, the NTSB issued a series of safety recommendations to address the need for improved data related to substance-impaired driving. In December 2012, through the NTSB's special investigation report concerning wrong-way driving on limited access highways, important safety recommendations related to alcohol ignition interlocks and Driver Alcohol Detection System for Safety (DADSS) technology were issued.

This safety report addresses the necessity for bold action; it will take stronger laws, swifter enforcement, and expanded use of technology to move towards zero impaired driving deaths.

What do the statistics tell us about alcohol-impaired driving?

According to the National Highway Traffic Safety Administration (NHTSA) Fatality Analysis Reporting System (FARS), in 2011, there were 9,878 alcohol-impaired driving fatalities, which represented 31 percent of all highway deaths. This represents a 53 percent reduction from the 21,113 people killed in crashes involving an alcohol-impaired driver in 1982. Tragically, since 1995, the proportion of fatalities associated with alcohol-impaired drivers has remained between 30 and 32 percent. In other words, progress to drive the number of deaths towards zero has slowed.

According to NHTSA General Estimates System database, in 2011, more than 173,000 people were injured in alcohol-involved crashes, including more than 27,000 who received incapacitating injuries. Moreover, nearly twice as many people in alcohol-involved crashes are killed or injured (32 percent) compared to those in non-alcohol-involved crashes (17 percent).

In addition the physical impact of these preventable crashes, there is a substantial economic toll. A recent study using 2006 crash data estimated that the total cost of alcohol-involved crashes was $129.7 billion, comprising $66.4 billion in monetary costs (such as medical costs, emergency services, market productivity, legal costs, travel delay, and property damage) and $63.3 billion in quality-of-life losses (reflecting how lives are changed as a result of a functional impairment, such as losing a limb).

How prevalent is alcohol-impaired driving?

According to the Centers for Disease Control and Prevention (CDC) Behavioral Risk Factor Surveillance System survey, an estimated 4 million individuals drove impaired and approximately 112 million alcohol-impaired driving episodes occurred in 2010. According to the AAA Foundation 2012 Traffic Safety Culture Index, despite the nearly unanimous rejection of driving after drinking too much, about 14 percent of respondents age 16 and over still reported having driven a motor vehicle when they thought they were close to or possibly over the legal BAC limit in the past year. In a 2007 NHTSA study of randomly stopped nighttime drivers, researchers found that nearly 1 in 20 drivers had a BAC of 0.05 or higher.

The Federal Bureau of Investigation estimated that 1.2 million DWI arrests took place in 2011. But it has been estimated that only 1 of 80 impaired driving trips result in the driver's being arrested.

What is the NTSB recommending?

The NTSB recommends a set of targeted interventions that will prevent crashes, reduce injuries and save lives. Specifically, the report makes recommendations in the following safety issue areas:

  • Reducing the per se blood alcohol concentration (BAC) limit for all drivers
  • Conducting high-visibility enforcement of impaired driving laws and incorporating passive alcohol sensing technology into enforcement efforts
  • Expanding the use of in-vehicle devices to prevent operation by an impaired driver
  • Establishing best practices for alcohol ignition interlock programs
  • Establishing best practices for driving while intoxicated (DWI) courts and using DWI courts and other programs to reduce recidivism by repeat DWI offenders
  • Establishing measurable goal for reducing impaired driving and tracking progress toward these goals

These recommended interventions apply to a range of driving populations. For example, lowering the per se blood alcohol concentration (BAC) limit and conducting high visibility enforcement target the entire driving population. Administrative license revocation and ignition interlocks for all offenders address those who have been arrested for DWI. DWI courts focus on those individuals most resistant to change, repeat DWI offenders. With the 19 safety recommendations that the NTSB has issued since the May 2012 forum, this reflects the NTSB's comprehensive approach to addressing a complicated problem.

Will these interventions really make a difference?

The NTSB set out to identify the most effective, scientifically based actions needed to reach zero crashes associated with alcohol-impaired driving. Examples of the effectiveness of these interventions include:

  • Fatal crashes decreased 18 percent in Queensland and 8 percent in New South Wales after those Australian states lowered their per se BAC limits from 0.08 to 0.05.
  • A review of 12 studies evaluating the effectiveness of sobriety checkpoints found that well-implemented and publicized checkpoint programs reduce alcohol-related fatal and injury crashes by about 20 percent.
  • Administrative License Suspension/Revocation laws are associated with reducing alcohol-related fatal crash involvement by 5-9 percent, representing at least 800 lives saved per year in the United States.
  • If all drivers with at least one alcohol-impaired driving conviction within the previous 3 years had used zero-BAC interlocks, approximately 1,100 deaths, or about 10 percent of fatalities associated with alcohol-impaired drivers, could have been prevented in 1 year.
  • A recent meta-analysis of drug courts and DWI courts estimated the relative recidivism rate for DWI court participants at 37.7 percent, compared to 50 percent for non-participants.

Why are these changes needed?

These recommendations are about addressing alcohol-impaired driving, which killed nearly 10,000 people and injured more than 173,000 people in 2011. In addition, the annual cost of impaired driving is $130 billion. The recommendations are part of the NTSB's bold roadmap to eliminate alcohol-impaired driving, reduce crashes, and prevent injuries and deaths. With physical, emotional, and societal costs this high, we can't afford not to take action.

Why does the NTSB recommend lowering the per se BAC limit to 0.05 or lower?

Three very specific reasons support the NTSB's decision to recommend lowering the per se BAC limit: (1) alcohol impairs critical driving tasks; (2) crash risk is consistently and significantly elevated by the time an individual reaches 0.05; and (3) lowering the BAC limit has been shown to reduce crashes, injuries, and deaths.

The scientific evidence shows that impairment begins with the first drink, and any alcohol consumption associated with driving reduces safety. A review of research findings from laboratory and driving simulator studies concerning the effects of alcohol on driving-related skills, such as divided attention, vigilance, tracking, perception, and reaction time, found that several types of performance are affected by BAC levels as low as 0.01. Another more recent study found significant cognitive decrements in speed of information processing, reductions in working memory, and increases in errors of commission at 0.04 BAC.

Regarding crash risk, one study found that the risk of fatal crash involvement at BACs between 0.050 and 0.079 ranged from 3 to 17 times greater, depending on the age of the driver and fatal crash. Another study found that at a BAC of 0.05, drivers are 38 percent more likely to be in a crash than are sober drivers. The crash risk is doubled at 0.07 and 2.69 times higher at 0.08.

Lowering per se BAC limits has been associated with reductions in impaired driving crashes and fatalities. For example, 14 independent studies conducted in the United States found that lowering the BAC limit from 0.10 to 0.08 resulted in reductions in alcohol-related crashes, fatalities, or injuries of 5-16 percent. A study of per se BAC reductions in several European countries found that the change from a 0.08 to a 0.05 per se BAC limit reduced traffic deaths by 8-12 percent among people aged 18-49. Fatal crashes decreased 18 percent in Queensland and 8 percent in New South Wales after those Australian states lowered their per se BAC limits from 0.08 to 0.05. Although lowering the per se BAC threshold may seem counterintuitive when the majority of alcohol-impaired drivers in fatal crashes have BAC levels well over 0.08, research on the effectiveness of laws limiting BAC levels has found that lowering the per se BAC limit changes the drink-driving behavior of drivers at all BAC levels.

What other organizations support a per se BAC limit lower than .08?

National and international public health and traffic safety organizations, including the American Medical Association, the World Health Organization, the World Medical Association, and the Association for the Advancement of Automotive Medicine, have advocated setting per se BAC limits at .05 or lower. The AMA, as part of its "Alcohol and the Driver" policy, has called for a per se BAC limit of .04 for more than two decades. In addition, more than 100 countries have already established per se BAC limits at or below 0.05.

How does this impact me? Can I have a glass of wine with dinner?

Safety involves understanding your risk and mitigating it. The scientific evidence shows that impairment begins with the first drink, and any alcohol consumption associated with driving reduces safety. Medical research shows that performance is affected with a BAC as low as .01. There are many websites and apps where people can find information to understand their particular risks if they choose to drink, but you can best mitigate your risk by not driving after drinking.

How can 0.05 laws be enforced? If a driver with a BAC of 0.05 may or may not exhibit obvious signs of impairment, how can they be identified?

0.05 BAC laws will be enforced the same way 0.08 BAC laws are enforced. Law enforcement officers will continue to need reason for a traffic stop and probable cause for an arrest. Officers employ a number of tools to identify impaired drivers, many of which will work to identify drivers impaired with BAC levels lower than 0.08.