As progress in reducing drunken driving deaths has stalled, a new report is suggesting states should lower the blood alcohol content threshold for drivers from 0.08 to 0.05.

Local experts, however, are questioning what kind of impact that would have.

The report, authored by a committee from the National Academy of Sciences, Engineering and Mathematics, said the BAC change could reinvigorate the fight to reduce the number of fatalities related to drunken driving. Since 2009, that number has hovered around 10,000 annually.

“Each alcohol-impaired driving crash represents a failure of the system, whether that is excessive alcohol service, lack of transportation alternatives, lack of clinical services, or lack of effective policies or enforcement,” the report states. “A coordinated, systematic, multi-level approach spanning multiple sectors is needed to accelerate change.”

In Waterford, drug recognition expert and Patrolman 1st Class Gil Maffeo said he thinks the idea is good on paper. After all, the science is there: In general, a person’s reaction time starts to slow as soon as his or her BAC hits 0.03, Maffeo said. Vision can be affected at 0.05, and coordination typically goes at 0.10.

To boot, the National Transportation Safety Board called for this more than four years ago, in a 2013 report that also encouraged the National Highway Traffic Safety Administration to provide incentives for states to adopt such measures. So far only Utah has lowered the limit to 0.05, and that just happened last March.

All of that said, Maffeo said there are issues with blanket BAC laws. For one, the factors that play into one’s BAC are vast. How much have you eaten? How often do you drink? How quickly do you drink? How big are you?

In his line of work, Maffeo said he has come across people above the 0.08 limit who largely are functional. He also has pulled over people who came in below the legal limit yet had noticeably slowed reaction times.

There’s also this: If such a law were passed in Connecticut, would it actually change the behavior of restaurant- and bar-goers?

“I’m all for it as a deterrent,” Maffeo said. “But you can make laws all day long. The question is whether or not people are going to adhere to them.”

Not much of a drinker himself, Maffeo takes a hard line on drinking and driving. It’s a choice he said most people are too willing to forgive.

He pointed to vehicular manslaughter charges as a prime example. The average intoxicated driver who kills someone else gets eight or nine years in prison. Most others who kill get at least three times that.

“Now, you have Uber. You have Lyft. In metro areas, there’s public transportation,” Maffeo said. “There’s just really no excuse.”

“We’ve excused people’s behavior,” he continued. “When someone gets liquid courage, we’re like, 'oh, they were drunk.' Until we say, ‘That behavior is inexcusable,’ we’re going to continue to have these problems.”

At the Connecticut Office of Mothers Against Drunk Driving, Executive Director Janice Heggie Margolis said the organization would keep a close eye on Utah but reiterated its long-standing stance: “The best choice is to not drink and drive, period.”

Rather than launching an effort to reduce BAC limits, Heggie Margolis said states might be better served to take after Connecticut, which requires all who are convicted of drunken driving — including first-time offenders — to install interlock ignition devices in their vehicles.

In the two-year period from July 2015 through May of last year, data show, the devices stopped cars from starting more than 135,000 times.

In the upcoming state legislative session, Heggie Margolis said her chapter of MADD will be lobbying against a push to decrease the fees associated with interlock devices.

“We have to maintain the integrity of the current ignition interlock device bill,” she said.

MADD also will be working on an immunity bill intended to protect those who draw blood to determine BAC levels. Heggie Margolis said many alleged offenders have lodged civil suits claiming their blood was drawn against their will.

Sarah Maloney, executive director of the Connecticut Restaurant Association, said the group works hard to educate its members on the safe service of alcohol. Maloney didn’t explicitly oppose the idea of a lower legal BAC but said the state should focus its efforts on repeat offenders.

“As responsible members of the community, our industry is very concerned about drunk driving,” she said in an emailed statement. “However, measures addressing this issue should be focused on repeat, chronic offenders who drink excessively, then drive — not the consumers that enjoy an adult beverage in a responsible manner with their meal.”

l.boyle@theday.com