Chart of "BAC Levels on Roads with at Least 20 Fatal Accidents"

U.S. roads with high average BAC levels. Chart courtesy AVVO study.

A study finds that among U.S. roads with at least 20 fatal car accidents in the years 2004-2013, Colorado’s US 6 is ranked fifth in those roads whose drivers had the highest average blood alcohol levels, a BAC of .224. (The average BAC of all roads whose data was examined was .19, as the study says.)

Arizona was ranked No. 1 on the list, with average BAC levels of .229 among drunk drivers involved in fatal car accidents on McDowell Road, the study finds, and North Carolina was No. 2, with an average .227 BAC level among drunk drivers involved in fatal crashes on US 74. “These numbers are extremely high, given a person with a BAC higher than .20 will need assistance walking, experience total mental confusion, and may possibly blackout,” the study says.

It Doesn’t Take Much

The report says that it is not difficult to drink enough to have such a high level of intoxication:

Although these BAC levels are very high, this level of intoxication can still happen quickly, even in a matter of a few drinks.

A standard drink serving is defined by alcohol content and serving size. For beer, this equals 12 ounces at 5% ABV (alcohol by volume); wine is 5 ounces at 12% ABV; and for spirits it’s 1.5 ounces at 40% ABV. These numbers may not reflect real-world scenarios, however. For example, craft beers with an ABV of 9% can put someone over the legal limit in as few as two servings. Consuming 4 pints of 9% ABV beer and a single shot of spirits within a three-hour period can propel a 160-pound person to a .20-plus BAC.

As Erin Marquis writes for Autoblog, the study, by AVVO, found that the roads most likely to have drunk driving crashes are those in the mountainous states of the west. A study by the National Highway Traffic Safety Administration (NHTSA) found that crashes in rural areas comprised 54% of all U.S. traffic deaths in 2013, according to the administration’s Traffic Safety Facts.

Interstate 90 in Montana is listed as the most dangerous such road in the U.S., Marquis reports, where there are 6.4 drunk driving deaths per 100,000 people, according to the study. However, because it appears in the top 10 most dangerous roads list three times, Wyoming is the most dangerous state, the report says. “The only area in the top ten that isn’t a rural Western state is Washington DC, which often finds its way on to any list of worst car accidents, congestion and road deaths,” Marquis writes.

Rural highways have the most such DUI numbers for several reasons, the AVVO study found. Those include that rural areas tend to have higher speed limits, poorer lighting, and more variable terrain, making it difficult for drivers who are navigating unfamiliar territory, the report says. Another reason for a higher level of drunk driving accidents on rural highways is that drivers in those areas are more likely to keep driving under the influence even if they have previous DUI convictions, and more likely to be impaired by a combination of alcohol and drugs, the study says.

Public Transit Options

Although a 2009 study on public transit found that public transportation can reduce drunk driving, the states with the most DUI offenders on the AVVO study’s list had “a general lack of public transportation — specifically to shuttle people to and from local bars,” the AVVO study writes. There are some rural areas in those states where public transit is available, the study found, but it is limited late at night (when people might be out at bars), and is generally designed for the senior and disabled communities. Nor are there ridesharing services in rural areas, the study notes. “This means that most people who go out to drink in rural areas will either have to drive home or spring for expensive cab fare,” the study says.

While there are many accidents involving middle-aged and older drivers, it is younger drivers who are responsible for “a disproportionately large” number of the crashes, the study says. Drivers aged 20-24 comprise only 8% of all licensed drivers, but were involved in 21% of all accidents between 2004 and 2013, the study found.

AVVO, a Seattle, Washington-based legal services company, conducted the study based on data from NHTSA’s the Fatality Analysis Reporting System. The study concludes by urging drivers not to drink and drive:

If you’re planning an evening where alcohol consumption is involved, arrange alternative modes of transportation home such as a designated driver, taxi, ridesharing service, bus, or subway.

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