Even as a recently released report suggests the rate of drunken driving continues to decline, statewide experts say much work remains.

According to a just-released study by the Substance Abuse and Mental Health Services Administration, the percentage of motorists who reported having driven drunk in 2014 was lower than the percentages in 2002 through 2012.

About 11.1 percent of people 16 or older, which would amount to 27.7 million people, told interviewers they had driven drunk within the past year. Males were more likely than females and young adults were more likely than adolescents and older adults to report having done so.

“Although the results of this study indicate that driving while impaired remains a problem in the United States, the analysis of data across time suggests that prevention messages or other factors may be having an effect,” the report concludes.

Just how much progress has been made is difficult to determine. According to data from the National Highway Traffic Safety Administration, 10,265 people died in crashes involving drunken drivers in 2015.

That’s 322 more fatalities than occurred in 2014. However, the rate of drunken driving fatalities per 100 million miles traveled, 0.33, is the same for both years because people traveled more miles in 2015.

And the percentage of overall driving fatalities that involved a drunken driver was lower in 2015 than in 2014. Over 10 years, though, that percentage varied by less than 3 percent, with a high of 32.06 in 2009 and the low of 29.25 coming in 2015.

Janice Heggie Margolis, executive director of Mothers Against Drunk Driving’s Connecticut office, said any increase in drunken driving fatalities is cause for concern.

Heggie Margolis said her office will continue to push for two things as a result: the expansion of the state’s Drug Recognition Expert program and a change in its ignition interlock device law.

Through the former, officers and troopers undergo more than 120 hours of initial training — including up to 60 in the field — so they can recognize impairment in drivers under the influence of drugs other than or in addition to alcohol.

DREs also can rule out medical conditions and specify into what category or categories a person's drug use likely falls.

As of November, the state had 31 trained DREs, including some stationed at state police Troop E in Montville and municipal departments in Waterford, Montville, Norwich and Groton Town.

In Connecticut, the court can order even first-time offenders to place ignition interlock devices in their vehicles for six months. The devices prevent a car from starting if a driver’s BAC is 0.025 or greater.

From July 2015, when that law went into effect, to July 2016, state Department of Motor Vehicles data show the devices stopped 58,000 engine starts, Heggie Margolis said.

As of July 2016, she said, more than 7,000 people had the devices in their cars.

Despite those numbers, which Heggie Margolis said are “significant,” MADD is concerned because the state requires a 45-day license suspension prior to device installation.

During that time, she said, people who choose to ignore their suspensions still can get behind the wheel while drunk. MADD would rather see the devices installed as soon as possible.

Amy Parmenter, manager of public and government affairs for AAA in Connecticut, wasn’t surprised by the SAMHSA study’s findings. Plenty of studies show drunken driving is on the decline, she said, and many factors are at play in that, from education campaigns and interlock devices to services like Uber.

Drugged driving, she said, is another story. She pointed to a recent AAA poll, which found that a majority of motorists don’t consider drivers who use prescription drugs or marijuana behind the wheel a serious threat to their safety. In the poll, drivers ages 18 to 29 said they drive after using marijuana more often than they drive drunk.

The SAMHSA study also acknowledges the use of drugs behind the wheel. The National Highway Traffic Safety Administration, it points out, found that an increasing number of weekend drivers had drugs in their system in 2013 and 2014 compared with 2007.

And, while the number of people reporting driving drunk declined from 15.3 percent in 2002 to 11.1 percent in 2014, the number of those who said they drove under the influence of illicit drugs went only from 5 to 4.1 percent in the same span.

The study's authors suggested information from surveys like SAMHSA’s could “help policymakers and prevention specialists in their efforts to reduce impaired driving.”

Efforts to combat drugged driving are particularly tough because there’s no measure for marijuana and other drugs that’s as simple as blood alcohol content is for alcohol.

“There is still a lot of work to be done to educate everyone about the dangers of drugged driving,” Parmenter said. “And, given that Connecticut lawmakers are considering the legalization of recreational marijuana, that work cannot be done soon enough.”

l.boyle@theday.com