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THE NEXT LOS ANGELES / TURNING IDEAS INTO ACTION : Getting Around : Are we creating a transit system that makes sense or simply a costly edifice that most Angelenos won't use? : Solutions: Targeting the Gross Polluters

July 17, 1994

FROM: Charles Lave, professor of economics at UC Irvine, who has studied transportation-related issues for 30 years.

Lave believes the time has come for Los Angeles to crack down on the region's worst-polluting vehicles.

"The single biggest change we could make to improve air quality is to get the gross polluters off the streets," Lave said.

Many experts say that cars account for almost half of the region's smog problem. In fact, most of Los Angeles' air pollution is produced by only 10% of the vehicles, the gross polluters. Cleaning up these cars would reduce automobile emissions by about 50%, which would be a significant dent in smog.

To snag polluting vehicles, Lave proposes using remote sensor devices that monitor a car's emission levels as it drives by. Enforcement officials with these gadgets could be posted on streets or freeways, and they would know immediately which of the passing cars emitted high levels of pollutants. Drivers would be pulled over and required to go through a smog inspection. Motorists whose cars fail would be ticketed on the spot.

Another approach would use equipment now available. The license plates of suspected polluting cars could be photographed, and the car's registered owner would receive a notice requiring a smog inspection. Failure to appear for the smog inspection would result in a fine.


This idea more than pays for itself. A six-month test program could be implemented for $2 million. This program could be run at 10% of the cost of the existing biennial inspections.


Remote sensors can now check passing cars for excessive emissions in a matter of seconds. With sensors installed at freeway entrances and exits, car owners would have no need for annual smog checks. Owners of vehicles that excessively spew out pollutants would be notified by mail. Here is how the sensor works:

1. Infrared source: An infrared beam is projected across a freeway entrance or exit.

2. Detector: A receiver picks up the beam on the other side and records a snapshot of a vehicle's emission.

3. Calibrator: The emission information is processed.

4. Computer: Data is analyzed by a nearby computer.

5. Video camera: A video camera keeps a record of every vehicle checked.


The receiver contains four detectors that view the infrared beam through separate filters. Three of the filters isolate pollutants. * Carbon dioxide * Carbon monoxide * Hydrocarbons

The fourth sensor, which picks up a spectral region that the pollutants do not absorb, is used as a reference.


A portable system, which includes the sensor, calibrator, computer, video camera and a van, costs an estimated $100,000 to $200,000.


Although the technology is young, incorporating remote sensors into a network with a centrally located computer command center could happen very soon.

Researched by DAVID F. MONTESINO / Los Angeles Times

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