COLUMBUS - The Ohio Supreme Court will decide whether police officers are allowed to stray from court rules when giving roadside sobriety tests to suspected drunken drivers.

The case justices heard Tuesday challenges a 2002 law that loosened the standards for when the tests can be used as evidence at trials.

The tests commonly include requiring suspects to prove their ability to walk and turn without stumbling, to stand on one leg and to smoothly move the eyes from side to side. The rules, approved by the Ohio Supreme Court, say the officers must adhere to federal standards for giving the tests, which can determine reasonable suspicion of intoxication. Instructions for breath tests are not involved in the current case before the court.

The National Highway Traffic Safety Administration has one set of commonly used standards for how to administer the tests, which include instructions on how to "score" various tests, such as the eye movement test.

The Ohio Supreme court is considering whether lawmakers overstepped their authority when saying officers only have to be in "substantial compliance" with the rules instead of following them exactly.

The case testing the relaxed rules was brought by John Boczar, of Ashtabula County in northeast Ohio, who tried to keep an officer from testifying about the sobriety tests Boczar had to perform when pulled over.

Boczar's attorneys argued that the officer had not strictly followed federal standards on how to conduct the tests. They claimed Ohio's law allowing officers greater leeway in conducting the tests infringed on the rights of courts to determine rules of evidence.

However, a county court allowed the officer's testimony and Boczar pleaded no contest to a charge of driving while intoxicated. The court said the new Ohio law gives a judge leeway in determining whether an arresting officer followed the rules when conducting roadside tests.

The 11th Ohio District Court of Appeals upheld the ruling.

Ohio's law grew out of a 2000 Ohio Supreme Court decision that threw out the conviction of a woman who claimed arresting officers did not strictly follow the National Highway Traffic Safety Administration rules for conducting roadside sobriety tests.

Justice Paul Pfeifer was among the justices who voted to throw out the 2000 case because the prosecution wavered from the strict adherence to testing guidelines. He said lawmakers crossed the line in allowing the adherence to be weakened.

"The General Assembly crowded in on this court's rule-making duty," Pfeifer said.

Sponsors of the law said it was needed because the standards for the tests were too strict and made it too easy for the courts to prevent prosecutors from using sobriety tests at trial.

The Ohio law permits judges to allow evidence if the officer conducted the tests in "substantial compliance" with the federal rules or other recognized standards but does not spell out what "substantial" means.