Gov. Phil Bredesen signed legislation June 8 giving the Tennessee Air Board power to require counties to conduct vehicle exhaust inspections by mid-2005. Idling restrictions on large trucks are also under consideration.

Under the new law, an inspection would be required before an owner can renew the vehicle registration. Motor vehicles failing the smog check would have to receive needed repairs to reduce emissions before going back on the road, The Associated Press reported.

The new rule follows the U.S. Environmental Protection Agency’s declaration in April that all or part of 18 Tennessee counties failed to meet federal standards for ozone pollution.

Small counties with fewer than 50,000 registered vehicles wouldn’t be required to set up a smog-testing program.

Barry Stephens, air pollution division director at the Tennessee Department of Environment and Conservation, told AP emissions testing is “just one tool in the box.” Among options are possible anti-idling rules for trucks and for the board to regulate industry.

“We’re trying to address the mobile sector more than we have in the past,” he said.