In an effort to discourage drunken driving and reduce traffic fatalities, advocates are pushing legislation that would lower the alcohol impairment threshold for Hawaii drivers.

Two bills in the Senate — SB 365 SD1 and SB 160 — and two in the House — HB 1281 and HB 1469 — would lower the blood-alcohol concentration limit for the offense of operating a vehicle while under the influence of an intoxicant from 0.08% to 0.05%.

According to Honol­ulu Police Department data, police investigated 47 traffic fatalities in 2021 — 23 of them alcohol- related. During that same year, HPD apprehended 2,473 drivers for impaired driving.

Rick Collins, project director for the Hawaii Alcohol Policy Alliance, said a statewide poll of 550 residents conducted between November and December indicated a majority favor the lower limit on blood alcohol level.

In recent testimony before the Senate Judiciary Committee, federal, state and county agencies, including the Honolulu Police Department and prosecuting attorneys for Honolulu, Maui and Kauai counties, came out in support of SB 160.

The Office of the Public Defender was joined in its opposition to the measure by the Kauai Beer Co., Lanikai Brewing Co., the Wine Institute and the Hawaiian Craft Brewers Guild.

“Progress toward eliminating alcohol-impaired driving fatalities has unnecessarily stagnated. More can and should be done to prevent these tragedies,” said Thomas Chapman, a National Transportation Safety Board member, in written testimony submitted for the Feb. 8 committee hearing.

Chapman pointed to what happened in Utah when legislation reduced the blood-alcohol threshold there to 0.05%: The state’s fatal crash rate decreased 19.8% from 2016 to 2019, when the law took effect. Meanwhile, the fatal crash rate across the nation went down just 5.6%, and neighboring states such as Colorado and Nevada did not see improvements similar to Utah’s.

The Utah study by the National Highway Traffic Safety Administration also found the new law had no effect on alcohol sales, tax revenue, tourism or the number of drunken driving arrests.

According to another study cited by Chapman, the risk of a car crash doubles when a motorist drinks enough to have a 0.05% blood alcohol level, and it doubles again at 0.08%, the current legal limit.

“The evidence is clear: per se (blood alcohol level) limits of 0.05% or lower can save lives and have saved lives,” Chapman wrote.

The state Department of Transportation called the 0.05% limit “a proven countermeasure that has reduced alcohol-impaired driving fatalities in other countries,” including Australia, Germany and Ireland. The threshold in Japan is 0.03%.

In written testimony, the Public Defender’s Office said a reduced threshold on blood alcohol level is “simply not necessary” because county prosecutors can successfully convict impaired drivers without providing evidence of blood alcohol level at trial. The agency argued the law would criminalize “the behavior of normally responsible drinkers without having an impact on reducing alcohol- related fatalities.”

Casting a wider net for drunken driving also would overburden police departments and congest the courts, causing delays in processing more severe cases of impaired driving, the Public Defender’s Office wrote.

The fact that Utah is the only state to have passed such a law “reflects that our society is not interested in criminalizing driving safely after consuming one or two alcoholic drinks.”

Similar bills to lower the blood alcohol level for impaired driving in Hawaii to 0.05% failed to advance during the 2022 legislative session.