California's South Coast Air Quality Management District is expected next month to approve the deployment of cameras on freeway on-ramps that will record millions of passing vehicles and issue warning letters to those it believes are polluting. The cameras will use laser sensors to measure hydrocarbons and other exhaust gases and will be spread in secret locations throughout Los Angeles, Orange, San Bernardino and Riverside counties.

Current law does not yet allow the devices to issue expensive citations, so the program will begin by offering incentives for "dirty" cars to be repaired or scraped. Those who get a notice can receive up to $500 in repairs at select community colleges or $1000 for agreeing to scrap the car.

For the past twenty years, California has required cars to have emissions tested before a vehicle's registration can be renewed. Current rules mandate annual testing for cars between six and thirty years old. Some see the new move as an admission that this smog inspection program has been a failure.

"We have known for at least 20 years that these inspection programs do not work particularly well," Joel Schwartz a former smog-check executive told the Los Angeles Times. "The evidence has been overwhelming that they are failing to repair the high-polluting cars. There is fraud. And yet they have been popular with regulators and activists."

Even as local smog regulators are moving ahead with the remote-sensor idea, state air quality officials have doubts about it. Some have questioned the accuracy of remote-sensing equipment, fearing that it will finger the wrong drivers by mistake.... A 2001 report by the National Academy of Sciences found smog-check programs generally failed to deliver the predicted pollution reductions, though it noted that they had made a positive impact.