CONCORD, N.H – (AP) Judges will soon be able to order people convicted of drunken driving to install special devices on their cars to monitor their breath alcohol levels.

“Right now we’re introducing the judges to the device, as well as reintroducing them to the law, and at least one company is ready to begin implementing them. We’re right on the edge of being able to do this,” said Judge Edwin Kelly, the administrative judge for the district courts. “I think there are many cases where a judge will find this is a great alternative to a license suspension.”

The devices act like a car key. The driver blows into a tube and the car won’t start if his or her breath shows a blood-alcohol level above a certain point. The devices also require random tests while the car is moving to ensure drivers don’t get someone else to start the car for them.

If the driver fails to blow into the machine during the rolling test, the horn will begin to sound and will not stop until the car comes to a rest. Once the car is stopped, it will shut off and cannot be restarted until an alcohol-free sample is provided.

The state passed a law in 2002 requiring the devices for some convicted drunken drivers, but they couldn’t be installed until companies were hired to provide and service them.

Offenders pay for the installation, monthly monitoring and resetting if a driver’s car ignition is locked repeatedly due to high breath alcohol levels.

On Friday, the Iowa-based Consumer Safety Technology, one of two companies hired to provide the devices, held a demonstration.

“Studies have shown the interlock devices cut down on the DWI recidivism rates,” said Dave Arringdale, a company representative. “While it isn’t foolproof, it has been shown to keep people who have been drinking off the roads.”

The interlock will cost $65 a month. Consumer Safety Technology said it plans to have 15 service centers across the state by mid-October plus three facilities with remote installation capabilities.

About 40 other states already use the devices.