The Legislature’s Transportation Committee has agreed on restrictions for communities that use automated license plate recognition systems that would require the information be purged after three weeks.

The devices, currently deployed only in South Portland, allow police to instantly record the license plate of passing vehicles and match them against a database of vehicles that are stolen or sought for some other reason.

The Maine Civil Liberties Union sought to ban the devices, saying they represent a significant government intrusion into residents’ privacy by recording where law-abiding citizens are at a given time.

The compromise, which would need to be passed by the full Legislature, requires all data collected by the devices to be purged after three weeks and restricts their use to police departments, the Maine Department of Transportation and the Maine Turnpike Authority.

The MCLU supports the compromise, saying the restrictions are important safeguards against abuse.