Maryland Gov. Harry Hughes today authorized a three-month program that will allow police to make random stops of motorists in an attempt to crack down on drunk drivers.

Hughes had shied away from the proposal for "sobriety checkpoints" when it was first suggested to him by state police last spring because he was wary of the civil liberties questions that might be raised during his campaign for a second term.

Today though, citing Attorney General Stephen H. Sachs' legal opinion that no civil liberties would be violated, Hughes announced the program would begin as a three-month experiment throughout the state on Dec. 12. That is the first day of "National Drunk and Drugged Driving Awareness Week."

Hughes announcement of the random checkpoints -- which have been used during the past year by police in Prince George's and Montgomery counties--was the focal point of his first news conference since his reelection and his return from a two-week vacation in Florida.

His right leg was stretched over a chair during the news conference because he cut his leg on a chaise lounge while in Florida. Hughes discussed a new prison, the expected $61.5 million budget shortfall the state is facing, possible gun control legislation and collective bargaining.

Hughes said the new random roadblocks are designed more as a deterrent than as a means of making arrests. "It isn't to arrest as many people as you can, it's to keep the drunken driver out of the automobile," he said.

At the suggestion of Sachs, state police will set up warning signs to let motorists know they are approaching a checkpoint.

"We did not think this was necessary constitutionally but I suggested it anyway," Sachs said. "This way, to a degree at least, people will be consenting to the stop. I liken this to going through a toll booth, that's about how long it will take. I think the very, very minimal intrusion is worth it considering the problem we do have."

Sachs said similar programs were being operated in other states. He said the stops were constitutional as long as all cars were stopped and as long as the contact did not go beyond "saying good morning" unless the officer had probable cause to continue.

On another topic, Hughes refused to answer questions about a report, delivered to him shortly before the Nov. 2 election, examining the role of Secretary of Transportation Lowell K. Bridwell in the controversial Westway Project in New York City. The report was written by Sachs, Speaker of the House of Delegates Benjamin L. Cardin and State Sen. John A. Cade.

Hughes said he would not comment on it until he receives Bridwell's reply to the report, which is expected by early next week. Bridwell also has refused comment.

Sources in the administration have said Bridwell was upset about the report, which reportedly criticized him for not being candid in his testimony on the project. Those same sources said the report was even more critical of the New York judge who accused Bridwell last June of "collusion" with state officials while he was project manager of Westway from 1972 to 1981. The sources said that Sachs, Cardin and Cade found the judge to be biased against Bridwell and predisposed towards being critical of him.

Hughes also said today that one of his legislative initiatives during the upcoming session of the legislature will involve strengthening penalties for illegal possession of handguns. Incoming Lt. Gov. J. Joseph Curran Jr. has long been a leading advocate of tighter gun control measures and his presence is expected to make the controversial topic more of a priority in Hughes' second term.

Hughes also must decide fairly soon where to locate a new prison that an upcoming report is expected to recommend. As he did throughout the campaign, Hughes refused to speculate today on where the prison might be built.

"If we're going to have another new prison, we're going to have to have a site," Hughes said. "And that means at some point, somebody, probably the governor, is going to have to say where it's going to go."