Utah’s 0.05 Percent Drunk Driving Limit Is Linked to Fewer Alcohol Crashes, IIHS Finds

• Utah remains the only state with a 0.05% blood alcohol limit, and the Insurance Institute for Highway Safety ties it to a nearly 9% reduction in alcohol-related crashes over four years.
• Against Arizona, Idaho and Colorado, the share of Utah crashes involving alcohol fell 12% to 21%, but the researchers say Utah’s drinking culture and the pandemic keep them from pinning down the size of the effect.
• Drivers in the other 49 states still face a 0.08% limit, and a Washington bill to cut it to 0.05% passed the state Senate 26 to 23 in January but has not become law.

Four Years of Utah Crash Data Give Other States a Test Case

Utah’s 0.05% limit took effect on Dec. 30, 2018, and the first four years of crash data link it to a nearly 9% reduction in alcohol-related crashes. The Insurance Institute for Highway Safety (IIHS) published the result on Oct. 27. No state has followed Utah: NHTSA states that a blood alcohol concentration (BAC) of 0.08 or higher is illegal in all 50 states, the District of Columbia and Puerto Rico, except in Utah, where the line sits at 0.05.

A per se law makes it a crime to drive with a BAC above a set limit even when the driver shows no sign of intoxication. A Utah driver who blows 0.06 breaks that law. A driver with the same reading in the other 49 states does not trigger the per se offense. NHTSA counted 2,028 people killed in 2024 in crashes where a driver’s BAC fell between .01 and .07, a range that starts well below Utah’s line and ends just under the 0.08 line everywhere else.

“Crash risk increases with the amount of alcohol in your system, but it spikes noticeably at 0.05%,” IIHS President David Harkey said. The finding lands in a country where alcohol-impaired driving killed 11,904 people in 2024, about 32 people a day or one every 44 minutes, NHTSA reports.

How the Researchers Handled the Pandemic and the Publicity

An earlier study found a substantial drop in fatal crashes in the first year of the Utah law, but the effect on alcohol-involved crashes stayed unclear. IIHS Senior Research Scientist Angela Eichelberger and independent researcher Scott Tippetts went back to the first four years of data and widened the count. The earlier work relied on police reports of alcohol involvement. The new study also counted crashes where alcohol-positive test results reached the file later and crashes where the driver refused a BAC test.

The researchers added two cross-checks. They tracked single-vehicle nighttime crashes, a stand-in for alcohol involvement, and they compared Utah before and after the law with Arizona, Idaho and Colorado.

The results run in the same direction. Relative to the previous several years, the share of Utah crashes involving alcohol dipped when the law passed and dropped a further 9% when it took effect. The share of injury crashes involving alcohol fell 12%. Against the three comparison states, where the rate of alcohol-involved crashes increased, Utah’s share dropped 12% to 21%, and the relative decrease was similar with the pandemic months excluded. The single-vehicle nighttime results were inconclusive.

The pandemic needed its own treatment. Alcohol-involved crashes in Utah spiked 46% in March through May 2020 under lockdown, a jump that faded fast. Across the 34-month pandemic period the monthly share of crashes involving alcohol rose 6% on average. IIHS examined two post-implementation windows, one before the pandemic and one covering the whole stretch. With those nearly three years removed, the reduction attached to the law grows larger, but the smaller dataset leaves it short of statistical significance.

Why Utah Is a Hard Test for the Rest of the Country

Three factors cloud the Utah result, and IIHS lists all of them. Utah has always had one of the lowest rates of alcohol-involved crashes in the United States, as many residents abstain from alcohol for religious reasons. The state also passed the 0.05% law with great fanfare more than a year before it took effect, and that publicity might have changed behavior early. IIHS handled the second factor by analyzing the period between passage and implementation on its own.

The researchers could not adjust for Utah’s alcohol culture. The study’s abstract goes further: it says the uniqueness of Utah’s alcohol environment and the confounding effects of the pandemic prevent the authors from determining the size of the effect. The nearly 9% describes Utah’s own experience. IIHS says a 0.05% limit might have less impact in other states, and could have more: with Utah’s baseline of alcohol-involved crashes already low, there was less room to move the needle.

A separate 2026 study in the American Journal of Preventive Medicine came at the question from another direction. Lead author Kaigang Li of Colorado State University and colleagues compared county-level crash deaths in Utah with counties in Arizona, Colorado, Idaho, Nevada, New Mexico and Wyoming, using federal crash data for 2013 to 2023. Alcohol-related crash deaths fell significantly more in Utah, while deaths not tied to alcohol showed no matching change. The reductions also reached drivers at higher BAC levels, well above the 0.05 line.

Opponents in Washington challenged the Utah record. At a January 2025 Senate hearing, a witness against SB 5067 told senators that traffic accidents had gone up in Utah after the state lowered its limit. IIHS measured the share of crashes involving alcohol, a figure that can fall even when total crashes rise, so the study does not settle that claim either way.

How 0.08 Became the Law Everywhere and Why Advocates Want 0.05

States began widely adopting per se laws in the 1980s. Limits started as high as 0.15% and stayed at 0.10% in many states for years. A limit of 0.08% became universal only in 2005, after the Department of Transportation made it a requirement for certain federal highway funds.

In 2013 the National Transportation Safety Board recommended that states drop to 0.05%. The agency argued that a BAC at that level significantly impairs depth perception and slows reaction time, and that other industrialized nations had seen immediate drops in fatal collisions after adopting a 0.05% limit. NHTSA’s effects table lists what happens at .05: drivers show reduced coordination, a reduced ability to track moving objects, difficulty steering and a weaker response to emergencies.

“These encouraging results from Utah should make other states take note,” Harkey said. “More than 10,000 people lose their lives in alcohol-related crashes every year in the U.S. We need to use every tool we have, including stricter BAC limits, to reduce that toll.”

Where the 0.05 Bills in Washington and Illinois Stand

Washington came closest. Senate Bill 5067, requested by the Washington Traffic Safety Commission and sponsored by Sen. John Lovick, would cut the limit from 0.08 to 0.05 for driving under the influence, for being in physical control of a vehicle and for operating a vessel. The version before the Senate would have taken effect on July 1, 2026, ordered a public information campaign, and required the Washington State Institute for Public Policy to report on the results by March 1, 2029.

Supporters told the Senate Law and Justice Committee that 75% of nations worldwide set their limits at 0.05 or lower and that the bill would not produce more arrests, as officers would keep arresting drivers who show signs of impairment. Opponents said it would catch drivers who are not impaired and miss high-BAC and repeat offenders. A third strand of testimony urged a two-tiered system that treats lower readings as lesser offenses.

The Senate passed the bill 26 to 23 on Jan. 28, 2026. The House Community Safety Committee held a hearing on Feb. 19 and took no action at its Feb. 24 executive session, and on March 12 the bill went back to the Senate Rules Committee without a House vote. The Legislature’s bill page lists nothing later, and the bill has not become law.

In Illinois, two Chicago-area lawmakers backed a bill that would cut the state’s limit from 0.08% to 0.05%, and it was pending in March. With Utah still the only state at 0.05%, no such bill has taken effect. A separate federal mandate, Section 24220 of the 2021 infrastructure law, directs NHTSA to require impaired driving detection in every new car, which goes after the same problem from the vehicle side.

What Drivers Should Do Whatever the Limit Is

NHTSA says it is very difficult to assess your own BAC or impairment, and that people often feel fine after several drinks. A person will likely be too impaired to drive before looking or even feeling drunk. A drink is a drink: one 12-ounce beer, one 5-ounce glass of wine and one shot of spirits each hold about half an ounce of alcohol. Several things move the number up or down. The count of drinks and the speed of drinking raise it. Food in the stomach slows absorption. Women generally carry less water and more body fat per pound than men, so more alcohol stays in the blood, and heavier people dilute the same amount of alcohol in more water.

Erin Doherty of Mothers Against Drunk Driving spelled out the practical rule in March. “You really should not get behind the wheel when you’re any kind of impaired, one drink, five drinks, whatever that looks like, just don’t drive,” Doherty said.

NHTSA lists the steps that work in any state. Plan the ride home before the first drink and pick a non-drinking friend as the designated driver. Call a taxi, a ride-hailing service or a sober friend if you drink. Take the keys from anyone who has been drinking and help arrange a sober ride. Hosts should make sure every guest leaves with a sober driver. Call local law enforcement if you see an impaired driver, and wear a seat belt on every trip.

The cost of ignoring the rule climbs fast. Penalties for impaired driving can include license revocation, fines and jail time, and NHTSA says a first-time offense can cost upwards of $10,000 in fines and legal fees. Many states make offenders install an ignition interlock at their own expense, a breath test device tied to the ignition that usually blocks the car above 0.02 BAC. In Utah the consequences now reach the license itself. Under House Bill 437, in force from Jan. 1, 2026, a court must designate anyone convicted of extreme DUI as an interdicted person, the legal step behind the red stripe on DUI licenses and the words No Alcohol Sale. That change came after the four-year window IIHS studied.

This year the national Drive Sober crackdown put extra patrols on the road from Aug. 19 through Labor Day, and the same advice applies every other week of the year.

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