Some automotive experts contend states are just robbing motorists of their time and money by requiring them to bring their cars in periodically for emissions testing.

Here's why:

• Since at least the mid-1980s, cars and trucks have been equipped with computer-controlled anti-pollution hardware -- which is largely self-policing.

• Current model-year cars and trucks are equipped with sophisticated On-Board Diagnostics systems.

• Tampering with the systems is no longer an issue since cars and trucks built since the 1980s were all designed with emission equipment as a part of their drivetrains -- and removal or tampering would interfere with their driveability.

• Those few cars that are 19-years-old or over and still on the road do not pose a threat to the environment -- since they constitute less than 5 percent of currently registered vehicles.

Source: Eric Peters, "Motorist Unfriendly Emissions Test Scam," Washington Times, December 22, 1998.