Drunk driving

DEFINITION: By law, a driver is considered to be impaired by alcohol if his or her blood alcohol content is 0.08 percent (0.08 grams of alcohol per 100 milliliters of blood) or higher. A driver is any operator of a motor vehicle, which includes motorcycle, truck, and passenger vehicles.

ALSO KNOWN AS: Alcohol-impaired driving; driving under the influence; driving while intoxicated

Drunk Driving Laws

The majority of countries worldwide had laws against drunk driving by the twenty-first century, though legislation differed depending on the country. Some countries, such as Romania and Malaysia, do not permit driving with any amount of alcohol in one's system, while other countries do not allow driving when one's blood alcohol content (BAC) is above a certain percentage. For example, the BAC limit in Peru is .05 percent, whereas the United Kingdom's limit (with the exception of Scotland) is set at .08 percent. Every US state has enacted a law making it illegal to drive with a BAC of 0.08 percent or higher. Also, each US state has set the minimum drinking age to twenty-one years and has established zero-tolerance laws that prohibit people younger than twenty-one years of age from driving after drinking. Zero-tolerance laws or other modified policies setting lower BAC limits also apply to some drivers in specialized roles, such as holders of commercial driver's licenses (CDLs). The majority of zero-tolerance laws set the drinking limit to a BAC of 0.02 percent. Drivers convicted of alcohol-impaired driving face suspension or revocation of their license, and repeat offenders may face even more severe penalties, such as fines or imprisonment.

Drivers who refuse to undergo BAC testing or who fail the test can have their license taken away automatically under a process called administrative license suspension, and the length of time a license is suspended ranges from fifteen days to several years, depending on the state. In most states, the most common license suspension lasts a year.

A mechanism that prevents suspended or probationary drivers from operating a vehicle while impaired by alcohol is the ignition interlock device. This device is attached to the vehicle’s ignition and forces the driver, before being able to start the vehicle, to blow into the device for an analysis of the driver’s blood alcohol level; a device that registers at or above the legal limit will lock the vehicle’s ignition. Feasibility studies are also underway to examine alcohol ignition locks for motorcycles.

Effects of Alcohol

Alcohol is quickly absorbed into the bloodstream and travels throughout the body and to the brain within thirty to seventy minutes of having an alcoholic drink. A standard alcoholic beverage (such as a twelve-ounce beer, a five-ounce glass of wine, or one shot of liquor) contains about one-half ounce (exactly 0.54 ounces) of alcohol.

All of these types of alcohol will affect BAC in the same way. How quickly a person’s BAC rises will depend on how quickly he or she drinks the beverage, the amount he or she drinks, the amount of food in the person’s stomach, and his or her weight and gender. Having food in the stomach helps slow the absorption of alcohol through the stomach walls into the bloodstream. Moreover, heavier people have more water in their body, and this water dilutes their BAC. Women typically have less water and more body fat than men, and alcohol is not easily absorbed into fat cells, so more alcohol is absorbed into the bloodstream.

The effects brought on by alcohol start to appear with a BAC of 0.02 percent. These effects include a loss of judgment and a decline in the driver’s ability to quickly track moving objects or perform two tasks at a time. Once a person’s BAC reaches 0.05, the risk of a fatal crash substantially increases. At this level, the person is less alert and coordinated, has trouble focusing, has trouble steering the vehicle, and is slower to respond to emergency driving situations. At a BAC of 0.08 percent, muscle coordination is poor and the driver will have problems concentrating and controlling the vehicle, will have short-term memory loss, will have problems processing information (for example, signal detection), and will show impaired reasoning and depth perception. With a BAC of 0.10 the driver’s reaction time and control deteriorates, thinking slows further, and driving becomes even more difficult. By the time a driver’s BAC reaches 0.15 percent, he or she shows a major loss of balance, impaired processing of information, inattention, and little control of the vehicle.

Statistics

The National Highway Traffic Safety Administration’s National Center for Statistics and Analysis (NCSA) tracks statistics on alcohol-impaired driving and reports these results annually. The NCSA states that any fatal crash in which a driver has a BAC of 0.08 percent or higher is an alcohol-impaired-driving crash, and fatalities resulting from this crash are alcohol-impaired-driving fatalities. They further clarify that alcohol-impaired does not mean that the crash or the fatality was solely caused by alcohol impairment.

Another source that monitors and reports statistics annually is the Insurance Institute for Highway Safety (IIHS). This organization uses data from the US Department of Transportation’s Fatality Analysis Reporting System to analyze and report statistics.

Fatalities

Some progress has been made to reduce alcohol-impaired driving and related injuries and deaths in the US since about 1980, though some years have seen upticks in deaths. Reports from the NCSA and the IIHS show that from 1982 to 1994, the United States had a 32 percent decline in deaths among drivers with a BAC at or above 0.08. This decline has leveled off in fatalities per year, and alcohol-related traffic fatalities declined by 23 percent between 2004 and 2013. Between the early 1980s and early 2010s, alcohol-related traffic deaths per population have declined by 50 percent, with the greatest proportional declines among individuals between the ages of sixteen and twenty. In the mid-1970s, alcohol was a factor in nearly two-thirds of all traffic fatalities; by 2013, alcohol was involved in roughly one-third of all traffic deaths. From 2012 to 2013, deaths in alcohol-related traffic accidents declined by 2.5 percent. In 2020, the National Highway Traffic Safety Administration (NHTSA) reported that 11,654 people died in alcohol-impaired crashes. This accounted for 30 percent of traffic-related deaths in the United States.

Time of day and day of the week also were important indicators of an increased incidence of alcohol-related-deaths. Midnight to 3 a.m. was the deadliest time for intoxicated drivers involved in crashes: 66 percent of all traffic fatalities at this time occurred in alcohol-related crashes and 55 percent of drivers involved in fatal crashes between midnight and 3 a.m. were alcohol-impaired. The incidence of alcohol-impaired drivers involved in fatal crashes was nearly four times higher at night (35 percent) than at daytime (9 percent) and was two times higher on weekends (30 percent) than on weekdays (15 percent).

The NCSA defined nighttime as starting at 6 p.m. and ending at 5:59 a.m. (daytime began at 6 a.m. and ended at 5:59 p.m.) and defined weekend as starting Friday at 6 p.m. and as ending Monday at 5:59 a.m. (Weekday was defined as Monday from 5 a.m. to Friday at 5:59 p.m.). The IIHS narrowed the timeframe for what defined nighttime (9 p.m. to 6 a.m.) and found that 59 percent of drivers with a BAC at or above 0.08 had died during that time, compared with 19 percent during other hours of the day.

Of 1,149 children age fourteen years and younger who were killed in motor vehicle crashes, two hundred (or 17 percent) died in crashes involving alcohol-impaired drivers. Of those two hundred children, 61 percent were in the vehicle of the alcohol-impaired driver and 15 percent were pedestrians or cyclists who were struck by the alcohol-impaired driver’s vehicle (data not reported on the remaining 34 percent).

Driver Characteristics

In the US in 2022, according to the NHTSA, 13,524 people were killed in traffic accidents involving at least one alcohol-impaired driver with a BAC of at least .08. This figure, which represented over a 14 percent increase over drunk-driving deaths in 2020, meant that alcohol played a role in roughly 31 percent of traffic deaths in the US at that time. Of the estimated 1.2 million road deaths per year worldwide, roughly 273,000 are estimated to involve at least one drunk driver.

In the United States, age was a significant predictor of a person driving drunk and being involved in a fatal crash. In 2020, drivers between twenty-one and twenty-four years of age and drivers twenty-five to thirty-four with a BAC of 0.08 or higher topped the list of those involved in fatal crashes at 26 percent each. Drivers thirty-five to forty-four years were invloved in 23 percent of fatal crashes. There was a consistently higher percentage of male drivers with a BAC at or above 0.08 percent who were involved in fatal crashes in every age group.

The proportion of drivers involved in fatal crashes with BACs of 0.08 or higher was 22 percent among male drivers and 16 percent among female drivers, 27 percent were motorcyclists, 23 percent were drivers of passenger vehicles, 19 percent were drivers of light trucks, and 3 percent were drivers of large trucks. Drivers involved in a fatal crash with a reported BAC level of 0.08 or higher were four and a half times more likely than nondrinking drivers to have a previous impaired-driving conviction. Among driver fatalities for which seatbelt use was reported, 66 percent were not wearing a seatbelt at the time of the crash.

Bibliography

“Alcohol-Impaired Driving.” National Highway Traffic Safety Administration, April 2022, crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813294. Accessed 22 Nov. 2022.

"Drunk Driving." National Highway Traffic Safety Administration, 2024, www.nhtsa.gov/risky-driving/drunk-driving, Accessed 31 Jul. 2024.

Madden, Duncan. "Mapped: The Drink Driving Legal Limits For Every Country." Forbes, 30 May 2019, www.forbes.com/sites/duncanmadden/2019/05/30/mapped-the-drink-driving-legal-limits-for-every-country/. Accessed 31 Jul. 2024.

"Mothers Against Drunk Driving." MADD, madd.org. Accessed 31 Jul. 2024.

Uddin, Hojol. "Drink Driving Statistics around the World." JMW, 10 Jul. 2022, www.jmw.co.uk/services-for-you/motoring-law/blog/drink-driving-statistics-around-world. Accessed 31 Jul. 2024.