Two Montgomery County judges, in separate cases, have ruled that roadblocks set up by county police to crack down on drunken drivers are unconstitutional. Their rulings contradict a third judge who ruled last month that they are legal.

Despite the new rulings, Montgomery police said they will continue to operate the "sobriety checkpoints," pointing out that under Maryland law, decisions by lower-court judges are not binding on other judges in the same court or in other lower courts and do not set precedents in the law.

District Judge William C. Miller, in a ruling last Thursday, said police who arrested Francis Lansdale at a roadblock last Nov. 29 were on a "fishing expedition resulting in a constitutional intrusion."

In a similar hearing on Tuesday, District Judge Stanley Klavan concluded that police had no right to stop Gary Kaetzel at a roadblock in Olney on Dec. 12.

"I consider these roadblocks to be an unlawful and illegal intrusion on the rights of our citizens," Klavan said.

In taking the opposite view, Circuit Judge John J. Mitchell, also ruling in a motion to suppress evidence, said he considered the roadblocks legal and only a brief inconvenience for citizens stopped by police.

Klavan said, "It is very difficult for judges at the District Court level to make these kinds of major policy decisions. But we do not have an appellate court . . . and District Court judges are put on the spot."

Police Chief Bernard Crooke said yesterday, "We will continue to enforce the DWI program and will continue, on a limited basis, to use the checkpoints as one of the enforcement efforts, pending an expeditious review of the courts' decisions."

Police Capt. John W. Baker, commander of the Wheaton district, where the checkpoints began last Oct. 30, said the roadblocks, which since April 1 have been set up daily in each of the county's five police districts, have reduced alcohol-related fatalities and arrests. He said that indicated to police that fewer drunken drivers are willing to take their chances on county roads.