One of the most effective ways to reduce smog is to get older polluting autos off the road, especially those produced before 1970 when the first rudimentary emission controls were required.
It's not a panacea for the air pollution problem, which continues to increase with the rise in the number of motor vehicles and total miles driven.
But it can, under certain circumstances, help to reduce the heavy pollution load caused by the 18 percent of older (pre-1980) cars that are still operating on the highways. One such vehicle can cause as much harmful air pollution as 20 new cars.
Crown Central Petroleum Corp. is offering to buy up to 100 pre-1977 clunkers for $700 each and scrap them, in a gesture to help improve the Baltimore area's air quality. It's a public service program that deserves commendation and support.
The accelerated motor vehicle retirement idea has been tried elsewhere with some success. It provides the most bang for the buck when used in small-scale, short-term programs in areas that have a severe ozone pollution problem.
The clunker-junker scheme is one that other companies may be adopting in the future, to buy emission-reduction credits as an offset against their own air pollution. (Although the federal mandate to reduce single-commuter auto trips in dirty air areas such as Baltimore has been weakened, utilities and other businesses are still under pressure to cut back their air pollution.)
Crown Central's offering price for oldies won't attract vintage collector cars. It is limited to autos that are legally registered and operating -- and polluting. One study by the Resources for the Future research organization found that $700 may be the most effective price to acquire and retire the filthy, yet marginally usable vehicles that still have several years of use remaining.
Reducing pollutants in vehicle fuels, developing cleaner-burning engines, promoting mass transportation and ride-sharing as alternatives to individual car trips are all programs that will help to clean up our air. Motor vehicles, after all, are the major contributor to lung-irritating ozone pollution.
The Crown Central program may not make a major dent in overall ozone levels, removing only 100 old cars. But it demonstrates yet another option for addressing Baltimore's dirty air problem.