PIERRE, S.D. (AP) — Twice a day for three years, Chris Mexican has showed up at the county jail in Pierre to blow into a tube and prove he hasn't been drinking.
After several drunken driving convictions, it has allowed him to remain free and to become a better, more clearheaded father to his kids. The 43-year-old carpenter worries about losing the routine when he completes the program as early as Christmas Eve.
"If I do ever drink again, I get all that misery back. I get refunded that if I want, and this if I want," Mexican said, motioning toward the locked building.
South Dakota's 24-7 sobriety program has helped curb drunken driving and domestic violence, and some incentives for states that adopt the model were included in the $305 billion transportation law that President Barack Obama signed Friday.
The program offers those accused or convicted of an alcohol-related crime an alternative to jail. The provision in the highway law, pushed by U.S. Sen. John Thune, creates an incentive grant totaling about $18 million over four years for states that implement the sobriety program.
It's akin to existing funds for states that have adopted seatbelt requirements or ignition interlock laws.
"This will give other states a chance to find out if it works as well," said U.S. Sen. Mike Rounds, who was South Dakota governor when the program began.
The new transportation law also allows states that implement a 24-7 program to avoid a penalty that routes construction funds to highway safety.
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 arrests by 9 percent in its first five years.
"These are large reductions when you consider that we're talking about the community level," said Beau Kilmer, who conducted the study and continues to research the program.
Experts say incentive grants are an effective way to encourage states.
"When it's a federal law, the word spreads and other communities that are looking for solutions find out about it, so they're much more likely to adopt it themselves," said safety advocate Joan Claybrook, a former National Highway Traffic Safety Administration chief.
South Dakota started the practice in 2005. Participants come to a site each morning and evening to blow into an alcohol breath test. Those who live farther away or who have difficulty remaining sober wear alcohol-monitoring bracelets or have ignition interlock systems in their vehicles.
Over the past decade, nearly 40,000 people have participated in South Dakota's twice-daily program, compiling a pass rate of more than 99 percent.
North Dakota and Montana have started similar monitoring systems, and more states are running or planning pilot programs.
South Dakota's attorney general, Marty Jackley, has also discussed the program with his counterparts in other states.
And West Virginia Attorney General Patrick Morrisey said South Dakota's "very positive" results warrant examination by his state, where a program would require legislative support.
"One of the benefits of having 50 states serve as experiments is you can learn from states that are applying new laws successfully," Morrisey said.
Some national organizations don't favor 24-7 used on its own. For example, Mothers Against Drunk Driving's priority is pushing for strong ignition interlock laws in every state because the measure is proven to be effective, Chief Government Affairs Officer J.T. Griffin said.
The 24-7 program isn't perfect. Some people still drink by calculating how much they can consume between tests without getting caught, though many are eventually busted.
At the Hughes County Jail on the east side of town, Brian Drapeau, 44, said he blew about twice the legal driving limit at an evening test for the program about a month ago. He said drinking vodka alone in his apartment led to half a day in jail.
"It was pretty tough on everybody," he said. "Sitting in there for 12 hours is just like, 'what am I doing?'"