AFTER YEARS OF sitting by idly watching the carnage mount on our highways, South Carolina finally starts a proven life-saving program on Friday, when we allow our police to enforce the state’s seat belt law.

Actually, the proven life-saving program already started earlier this fall, when the Highway Patrol stepped up its outreach program, designed to convince more people to buckle up.

The patrol has worked on mass-market outreach for years, but it has launched a grass-roots initiative thanks to a mandate in the seat belt law. So far, that program has included speeches to community groups and meetings with leaders in the Hispanic and African-American communities, both of which have far lower seat belt usage rates than whites. Officials are trying to get churches in those communities to help spread the word. (The other low-use group, 18- to 34-year-old men, is harder to target through grass-roots efforts.)

That outreach may have nearly as much effect as the part of the law that gets all the attention — the provision that lets police treat the seat belt law like every other law, stopping people simply because they are violating it.

Most people obey the law merely because it’s the law. And while state law has required people to use seat belts for nearly two decades, it was an unenforceable law, so the mythology grew up that it wasn’t even the law. In their outreach efforts, police are making sure everyone knows what the law requires of them.

They’re also making sure people understand why wearing a seat belt is required: It saves lives, and not just occasionally. Wear a seat belt, and your chance of surviving a crash increases by 45 percent to 60 percent. Your chance of avoiding serious injuries increases by 50 percent to 65 percent. Your chance of not being thrown from the vehicle — and thus of staying in control well enough to avoid running into other people — increases by as much as 70 percent.

A spokesman for the Highway Patrol noted that the biggest thing needed now to make our highways safer is more personal responsibility. He’s right. That would solve a lot of our problems. And a lot of people learn personal responsibility from their parents, their churches, their schools. More should.

But some people need a law to teach them to act in a responsible way. The seat belt law can do that, particularly if police will enforce it.

If South Carolina follows the pattern of other states, the portion of people wearing seat belts will go up by 10 to 15 percentage points over the next year. That will translate into more than 100 lives saved — and avoid a repeat of what is expected to be a record-breaking highway death rate this year. It will translate into 1,700 people avoiding a trip to the emergency room every year. It also will save South Carolinians $200 million in direct and indirect economic losses every year.

And it will allow highway safety advocates to turn their attention to giving police other tools they need to make our highways safer, from more troopers on the highways to a set of penalties that are strong enough to keep people with suspended licenses from driving to a drunken driving law that isn’t riddled with loopholes.