With decades of proof of how dangerous drunken drivers are to themselves and to others on the road, it might be nice to believe that the simple social and moral stigmas against drunken driving would be enough to curb it. But drunk driving continues to be a problem in Virginia (albeit a diminishing one), so the stigmas clearly haven’t been completely effective.

But shame isn’t the only thing working against drunk drivers who get caught and convicted. Experts estimate that the average first-offense DUI will cost the motorist many times the amount of the fine the court levies. In fact, they say, when things like extra insurance costs, legal fees, towing fees and court costs are added in, the total cost of a DUI conviction rises to anywhere between $5,000 and $20,000. And accounting for such hard-to-quantify things as lost wages and even lost jobs can send that total into the stratosphere.

But even draining bank accounts in the name of punishment has not been completely effective in removing drunk drivers as one of the dangers other drivers face each day. In 2009, there were more than 27,000 drunk-driving arrests in Virginia, according to the FBI’s 2009 Uniform Crime Report. Even sadder were the 243 alcohol-impaired driving fatalities reported by the National Highway Traffic Safety Authority.

Considering the human impact of what is, in the end, a completely avoidable behavior, Virginians should be glad for a new law to require that ignition interlock devices be installed in the vehicles of those who are convicted of driving while intoxicated, even if it’s their first time facing such a conviction.

The devices are designed to require drivers to pass a breath test before the car’s ignition is released. They will be expensive to install and maintain — yet another added cost to the convicted DUI offender. But that’s not the main reason they’ve been approved by the General Assembly and the governor. Ignition interlock devices are by their very nature intended to keep known drunken drivers from repeating the crime that got them arrested in the first place.

Repeat offenders are a significant part of Virginia’s drunken-driving problem. The ignition interlock law will reduce the impact they have on the commonwealth’s level of road safety. It also will help teach first offenders to plan ahead for safe alternatives to drunken driving.

It’s a winning law for Virginia, one that citizens of the commonwealth can expect to have measurably positive results. Its passage was a bright spot in an otherwise rancorous and sometimes shameful General Assembly session.