Two years after its last experiment with smog check spy cameras California's South Coast Air Quality Management District (AQMD) is reintroducing and expanding its program designed to accuse motorists of polluting. The "High Emitter Repair or Scrap" cameras will photograph passing vehicles, scan license plate numbers and record driver identities in a database. If the machine thinks an SUV or old car or pickup truck is a "gross polluter," its owner will be mailed a notice.

For now, the program will not be sending tickets. Instead, a $4 million appropriation from gas tax funds allows the agency to offer the accused motorist $500 in vehicle repairs at a participating community college. The owner may also accept $1000 to $2000 in cash if he is willing replace the polluting vehicle with a low-emissions used or new car. The emissions cameras are expected to make millions of vehicle scans, but only a few hundred cars will end up being repaired. An earlier version of the program that ran between 1996 and 1997 scanned 19 million cars but only repaired 600.

Made by Environmental System Products, the spy cameras will be moved every few days among a hundred freeway onramp sites in four counties. AQMD refuses to disclose site locations. The AccuScan device works by projecting ultraviolet and infrared beams across the roadway. Emissions from the vehicle's tailpipe will absorb some of this light, allowing a roadside sensor to measure the remainder. From this, the system estimates hydrocarbon, carbon monoxide and nitrogen oxide levels within a second.