Solutions for smog reduction idling?

For almost two decades, experts have said that one good way to reduce smog in places such as the valley is to find and fix the very dirtiest cars and light trucks.

So-called gross polluters, generally those emitting at least twice the allowable pollution, make up fewer than one vehicle in 10. Yet they account for three-fourths of illegal emissions.

Studies have shown that many of those vehicles somehow evade the Smog Check program, which is supposed to get them off the road. But solutions must run a gantlet of opposition from bureaucrats who won't acknowledge Smog Check's failings -- or accept that an alternative might work better.

Just last year, an analysis showed that Smog Check is as likely to give a polluting vehicle a passing grade as to fail it, and that two in five failing vehicles will fail again within six months of being repaired.

The state-run program's flaws leave agencies such as the San Joaquin Valley Air Pollution Control District grasping for ways to reduce motor vehicle emissions. The district's main answer: Track down almost 3,000 gross polluters per year and take them off the road. The main problem: Not enough money.

Instead, the district is launching a three-year program to target 600 of an estimated 43,000 gross polluters on valley roads. At that rate, it would take more than 70 years to round up all the region's dirty vehicles, assuming no new gross polluters enter the picture.

Doug Lawson, a former state Air Resources Board scientist and a longtime critic of the Smog Check program who now works for the National Renewable En-ergy Laboratory, says Smog Check has a fundamental problem: It focuses on testing cars when it should focus on finding and fixing gross polluters.

The program tests millions of clean cars per year. But in the process, it somehow misses perhaps hundreds of thousands of gross polluters.

And that, Lawson says, is the main argument in favor of alternatives: "If Smog Check were working as well as they say it is, then it would be finding and fixing the high emitters. But it isn't." To drive a gross polluting car is illegal, but enforcement is rare outside of registration.

Beyond that, gross polluters are hard to categorize. Many are old, but some are nearly new, transformed into gross polluters by poor maintenance or tampering. Some are owned by scoff-laws who don't register their cars and never get smog tests. Some get tests from dishonest shops.

A surprising number fail the test, get repairs done, then pass, only to have emissions rise again within weeks or months. Whether that's because of inadequate repairs or new, unrelated breakdowns is not clear. But the state's random roadside tests show about 40 percent of failed-then-repaired cars fail again in six months.

The challenge lies in finding a way to identify gross polluters and get them off the streets, forever or at least until they can be fixed properly.

'Remote sensing' touted

University of Denver chemist Donald Stedman says he thinks he has the answer. In the mid-1980s, his lab built a device that can measure emissions by focusing a light beam on a car's exhaust as it drives by. Ever since, he has been arguing that it is the best solution to catching the cars that slip through the Smog Check net.

More than a dozen studies have shown that the device can reliably scan hundreds of cars and pick out the handful with emissions that greatly exceed legal limits.

Yet regulators at the state air board and federal Environmental Protection Agency have a long history of resisting proposals to use Stedman's "remote sensing" or similar technology to tackle the challenge of tracking down gross polluters between Smog Checks.