SIOUX FALLS, S.D. — Every day before sunrise, people stream through a nondescript door behind the county jail in South Dakota’s largest city.

Wearing neatly pressed business suits, neon-green construction uniforms or even wrinkled pajamas, they’re all here for the same reason: to prove they’re not drunk.

These are participants in a South Dakota program that aims to reduce drunken driving and domestic violence by requiring offenders to prove twice a day that they have not been drinking.

In return, they stay out of jail.

Bolstered by South Dakota’s success, the approach is now gaining momentum nationwide. North Dakota and Montana have started similar monitoring systems, and at least five more states are running or planning pilot programs. Other states are passing legislation to do the same.

South Dakota started the practice in 2005, offering those accused or convicted of an alcohol-related crime an alternative to jail. Participants are required to come to a testing site every morning and evening to blow into a Breathalyzer. Those who live farther away or who have trouble staying sober between tests wear alcohol-monitoring bracelets or have ignition interlock systems in their vehicles.

Participants who fail the test, or “blow hot,” are immediately jailed: 12 hours for the first offense, 24 hours for the second. If they fail a third time, they’re incarcerated until a judge decides their fate.

Those who run the program herald it as a common-sense solution to high rates of repeat drunken driving and domestic violence and a way to ease overcrowding in jails, which was why it was started in South Dakota.

The state once had one of the nation’s highest rates of DUI arrests, and jail overcrowding was becoming a serious issue. That’s when the program was created by then-Attorney General Larry Long.

“Simply warehousing people with chronic alcohol and drug offenses doesn’t work. It’s never worked. And the key is changing behavior,” said former Deputy Attorney General Bill Mickelson, who started working on the program in its infancy and now runs a consulting company that works to spread the idea to more states.

State officials are also quick to point out that the programs basically cost taxpayers nothing after they are up and running. Participants bear most of the financial burden, typically paying $1 to $3 per test.

Over the last decade, more than 37,000 people have participated in South Dakota’s twice-daily Breathalyzer program, compiling a pass rate of more than 99 percent.

At the Minnehaha County Jail in Sioux Falls, people of all stripes come during a three-hour window. Many stop on their way to work and again on their way home.

“I’ve been drinking for a long time,” said Darryl Nave, a 52-year-old chef dressed in kitchen garb who’s been in the program twice before. “I blew hot a couple times, and then I did realize I can’t lose my job. I need my job. I’m supporting my family again.”

An independent study released in 2013 by the RAND Corp., a nonprofit think tank, found that South Dakota’s program cut the rate of repeat DUI arrests at the county level by 12 percent and domestic violence offenses by 9 percent in its first five years.

It was surprising at first that domestic violence offenses dropped by so much. But research has found that requiring large numbers of young-to-middle-aged men not to drink, even for a little while, can affect other behaviors, said Beau Kilmer, who conducted the study and continues to research the program.

In Montana, the state started pilot programs in 2008 and expanded the system to 36 of its 56 counties. Preliminary research shows recidivism rates dropping by 40 to 70 percent.

One of the pilot programs is in Jacksonville, Florida, where authorities previously used ignition interlock systems. But studies showed that fewer than half of offenders ever got them installed, choosing instead to drive illegally or not at all.

“Quite frankly, we didn’t know if what works in South Dakota and some of these other states would really be the case in Florida,” said Sue Holly, executive director of the Northeast Florida Safety Council, which oversees the program. “But we are seeing similar results. We are seeing people’s lives changed.”

The program isn’t perfect. Administrators and participants at the Sioux Falls testing site acknowledged that some people still drink by calculating how much they can consume between tests without getting caught, but many are eventually busted.

For six months, Dan Fratze said he would drink vodka immediately after each test and be sober by the next one. It worked for a while.

Fratze, who said he has multiple DUIs, now wears an alcohol-monitoring bracelet that he said has helped him quit drinking. The bracelet monitors a person’s “insensible perspiration” every 30 minutes and alerts authorities if the device is tampered with.

For Eric Metcalf, a 21-year-old Sioux Falls man, the program has kept him accountable and sober at times when he said he needed it.

In March, he was arrested on suspicion of driving drunk and placed in the program, since it was his second DUI. Then in May, his brother was fatally shot in Rapid City, an act authorities believe was premeditated.

At the time, Metcalf said, he was depressed and worried he might do something he would regret. But he didn’t, and now he plans to enter a substance-abuse program in Sioux Falls.

The regular tests, Metcalf said, “kept me sober during that time. Being on the program helped save my life, I guess.”