A dangerous and absurdly lenient sentence this week for an Aurora man convicted of his sixth DUI arrest — this time with a blood-alcohol level three times over legal limit — illustrates how far Colorado has to go in using the law to protect the public from drunken drivers.

Doyle Carmack, 54, was sentenced by an Arapahoe County judge to five years probation, and no jail time at all, after he was convicted of drunken driving stemming from an arrest in March.

Aurora police said they saw Carmack driving erratically and pulled him over, measuring his blood-alcohol level at 0.235, three times the legal limit, according to police and court reports. Records show he was convicted five times previously of drunken driving in Missouri.

Now, Carmack is back on the roads.

Arapahoe County DA George Brauchler was infuriated by the timid sentence, especially in light of a recent law enacted by state lawmakers that makes repeat drunken driving offenders felons. Prosecutors had asked for four years in prison and got none.

The judge was right not to send Carmack to prison at taxpayers’ expense, but he was wrong to not do more to prevent this serious repeat offender from driving drunk again and injuring or even killing someone in the future.

Sending most drunken drivers to jail does little or nothing to prevent them from continuing to drink and drive. Most are alcoholics and they will lie, cheat and connive to continue to drink, and most likely drink and drive. That’s the nature of the disease.

About two-thirds of all deaths caused by drunken drivers are committed by people facing their first DUI arrest, not their second, third or fourth. It’s the first time their drinking and driving connected them to law enforcement. However, research shows that the average drunken driver motors their car many times while inebriated before they cause a crash or run into the law.

Felony DUI repeat offender laws haven’t reduced drunken driving arrests in the other 46 states that have created similar laws. The rate of DUI charges across the country has fallen in states that have created such felony laws at the same rate as states (such as Colorado) that did not impose such felony convictions.

And jailing an already troubled alcoholic only makes it more likely they’ll become unemployed, exacerbating their problems and making it even more likely that they’ll be long-term recipients of costly public assistance.

It’s not that we’re trying to defend people who arguably deserve to go to prison for endangering or harming other motorists with their drunkenness; it’s just that sending DUI offenders to prison doesn’t make the streets safer, and it costs taxpayers huge sums of money.

Drunken driving deserves much more serious attention in Colorado. About 150 people are killed in the state each year because of intoxicated drivers. And about 25,000 people are arrested in the Colorado each year for driving under the influence of alcohol.

It’s a problem of enforcement and compliance, not jail time. Arrests do little to stop the worst offenders. Fines do little. Confiscating driver licenses do little. Research shows that about 75 percent of people who lose their licenses because of drunken driving keep right on driving, even in states that already impose felony convictions.

A realistic solution forces drunk drivers into treatment, forces them to take Antabuse-like medications or undergo daily blood-alcohol checks at their own expense. It forces them to install mandatory drunk-driving ignition prevention systems in their cars and at their own expense. These interlock systems are far from perfect, but they shift the cost of keeping drunks off the road to the drunks themselves, and not taxpayers.

Even all of this won’t end drunken driving in Colorado. Because we are a society that bestows so many liberties, it’s impossible to find a perfect solution. But actively preventing these dangerous alcoholics from getting access to alcohol and automobiles is far more effective than simply locking them up to commit the same crime and soon as they get out.