Going Mobile

On-road emissions tests promise a cheap and effective way to clean up auto pollution.


At a busy intersection, an ordinary-looking van waits by the roadside. Inside, two people watch a series of gauges and a video monitor. A passing car grabs their attention. They radio ahead to a waiting policeman, who motions the car to the curb. The policeman informs the driver that he is violating the law.

No, this isn't "Mission: Impossible." It's a test conducted in Los Angeles to monitor auto pollution. The driver in question was violating state emissions regulations, but the policeman simply asked him to open his hood and then checked the car's pollution-control equipment to recommend repairs.

The same method, however, could be used to enforce emissions standards. It would be a nonintrusive, inexpensive way to tackle auto pollution across the country. The researchers who developed this mobile monitoring system say it accurately identifies polluting cars. Widespread use of their system, coupled with measures requiring polluters to tune up their cars, could replace vehicle smog inspections and dramatically reduce the airborne pollutants released by automobiles.

Despite its advantages—and in a sense, because of them—the system has been largely ignored by environmental groups and regulators, who prefer to pursue their own agendas. Environmental advocates who want to influence policy have developed their own pet projects and seem blind to alternative approaches, no matter how promising. Bureaucrats are more interested in maintaining and expanding their power than in addressing environmental problems. A viable solution has gotten lost in the shuffle.

Donald Stedman, a chemistry professor at the University of Denver, decided nearly two decades ago that auto-pollution testing should monitor cars on the road, not just those hooked up to diagnostic equipment in test garages. He has designed a portable sensing device to rapidly check cars and identify gross polluters. Along with other University of Denver researchers, Stedman has conducted more than 250,000 readings of cars in motion.

Stedman and his colleagues can set up a mobile testing unit on a freeway exit ramp or anywhere else it can monitor one lane of traffic at a time. An infrared sensor reads the emissions from each vehicle while a remote camera photographs the car's license plate. Within a few seconds, you have a photograph/readout of the car and its pollution level. The machine can test up to 1,500 cars an hour, unlike stationary garage tests, which take at least five minutes each. Stedman says half a dozen of the testing units, costing about $50,000 each, and a couple of vans could effectively monitor all the cars in a city the size of Denver.

The tests Stedman's team has conducted shatter a number of myths about auto pollution. For example, the prevailing wisdom is that all cars pollute, and that every old car pollutes more than any new one. Wrong, says Stedman.

"Seventy percent of the cars we test everywhere are as clean as me breathing," he says. He adds that a properly tuned car should emit less than 1 percent carbon monoxide under normal driving conditions (California's standard for new cars) and no more than 2 percent to 3 percent under the most severe engine strain. Studies conducted by the California Air Resources Board (ARB) and the Auto Club of Southern California basically accept that conclusion. But they differ with each other and with Stedman on what to do about car emissions.

Consistently, the dirtiest cars (classified as "gross polluters") identified by Stedman's mobile sensing unit emit at least 4 percent carbon monoxide. Stedman's data show that three-quarters of all cars built before 1975 (the first year U.S. cars were equipped with catalytic converters) run cleanly by his standards for a properly tuned vehicle. As the fleet gets newer, cars do become cleaner. Gross polluters represent 17 percent of 1975–79 model-year cars, 7 percent of 1981s and '82s, and only 0.3 percent of the 1988s.

But consider those numbers again: Three-quarters of the cars with virtually no pollution controls run cleanly. In fact, Stedman has found that, because drivers get rid of older cars in bad mechanical condition, the pollution caused by the cars in a given model year levels off after about 12 years. His tests show that cars from the '50s and '60s at classic auto shows—again, with no emission controls—tend to run as cleanly as new models just off the assembly line.

James Ortner, chief transportation planner for the Auto Club of Southern California and a planning professor at the University of Southern California, agrees with Stedman that properly maintained cars pose little, if any, pollution-related health threat.

But badly tuned cars, regardless of age, can be terrible polluters. Biochemist Gary Bishop, one of Stedman's colleagues, recalls a trip Stedman made to Capitol Hill, where he tested cars at the Rayburn Senate Office Building. One 1987 taxicab registered 13 percent carbon monoxide. "The guy drives 35,000 miles a year," Bishop says. "Thirteen percent at 35,000 miles [produces] six and one-half tons of CO. He was [also] losing 26 percent on his gas mileage. One gallon in four-right out the tailpipe." Mechanics found a defective fuel injector that cost less than $200 to repair; the car then emitted less than 1 percent carebon monoxide.

The possibility of such dramatic gains at relatively low cost suggests that designing cleaner cars is not the most effective way to control emissions. Since many automotive analysts believe that designers can't make cars much cleaner without making them a lot more expensive, policies that encourage drivers to clean up what they own now make more sense.

The Denver team has also destroyed another myth about auto pollution: that it's distributed along a smooth bell curve. Stedman's team has consistently found that fewer than 10 percent of the cars on the road cause 50 percent of the pollution. But federal and state officials craft policies that treat pollution as if it were normally distributed.

Gary Bishop says that Environmental Protection Agency tests in Denver show that the "average" (mean) car puts out 50 grams of carbon monoxide per mile. But the median is closer to 20 grams per mile. So tightening emissions standards for all drivers is much less effective at reducing pollution than targeting the gratuitous smoggers at the far end of the curve.

The Denver findings roughly match those conducted by the Auto Club. Ortner says that cars built since 1980, which have electronic exhaust catalysts, do little damage to the atmosphere as long as they're maintained at manufacturers' specifications. Both Ortner and Stedman say there's no need to impose tougher emissions standards on newer cars.

Since the 1970s, federal and state authorities have rightly considered auto pollution a serious health concern. The EPA reports that more than five dozen communities in 35 states currently oversee or plan to institute emissions-certification programs for automobiles. California's auto-emissions standards have been tougher than federal standards since 1962.

And real improvements have occurred. The EPA says 1990-model cars run 96-percent cleaner than their 1970 counterparts. The Clean Air Act of 1990 will attempt to reduce future auto emissions by another 50 percent to 75 percent.

But regulation has been less effective at controlling emissions from cars on the road in actual driving conditions. Although cars may leave the assembly line cleaner than ever, cars in use still pollute. California's Air Resources Board says motor vehicles cause around 60 percent of the air pollution in the Los Angeles Basin. But Stedman, Ortner, and other researchers have assailed the smog-inspection programs designed to preserve air quality. A program featuring mobile on-road testing could greatly reduce auto pollution—for a fraction of what the alternatives cost.

The Denver researchers have conducted tests in half a dozen cities in the United States and Canada. Twice in the past 12 months they set up voluntary programs with employees of Amoco and US West (the regional telephone company) to demonstrate how a pilot project might work.

Dave Liggett,a spokesman for US West says that when the company tested its employees' cars, "Many of them drove by the sensor and asked when the test started. They didn't realize they had already been tested."

For a citywide program, motorists would send in an inspection fee equal to the normal smog-test charge (Stedman calls it a "pollution insurance" premium) along with their annual car registration forms. "We would spend the same amount of money on pollution control," Stedman says, "but get some use from those dollars." Assuming 9 out of 10 cars barely pollute, and given that Stedman's tests are inexpensive to administer (about 50 cents each), the program would be self-financing. (California's smog-test program, by contrast, receives about $250 million in state subsidies each year.)

When a random test identified a gross polluter, that driver would receive a notice from the city government requiring him to either pay a fine or get a tune-up. Stedman even suggests that the city could use the program's "insurance fund" to issue "cleanup vouchers" to help pay for the repairs. Once a driver had been identified, additional violations could jeopardize his vehicle registration. Flagrant violators could have their cars impounded until they completed the necessary repairs. The tests aren't meant to be a type of pollution tax, but instead to get drivers to fix and properly maintain their cars.

The Auto Club's Ortner recommends a somewhat similar program using different technology. Newer cars have on-board diagnostic equipment to help mechanics identify problems. Ortner suggests that drivers can have mechanics connect their cars to computers that will give a detailed readout of emissions and of the mechanical condition of the pollution-control equipment. Drivers would send the readout to the Department of Motor Vehicles at registration time. As long as the car runs at manufacturers' specifications, the driver would avoid pollution fines.

Stedman says his mobile tests would be less complicated and much easier to administer. Ortner notes, however, that Stedman's test does not measure nitrous oxide—the major component of smog in Los Angeles, Milwaukee, and elsewhere. But Stedman says it's possible to redesign the equipment to measure other types of pollutants. Cities confronted with a variety of emissions problems could then benefit from mobile on-roadtesting.

Mobile tests also allow continuing improvement in air quality once today's grossest polluters clean up. After tuning up the cars that emit more than 4 percent carbon monodioxide, Stedman says, you could go after the next dirtiest cars; the process could continue until virtually every car operated cleanly.

Although its virtues are hard to deny, Stedman's approach has not caught on. Governments, businesspeople, and mainstream environmental groups concerned about auto pollution have instead focused on alternative fuels, old-car buybacks, and periodic smog inspections. Each of these programs promises smaller gains at greater costs.

When President Bush released his clean air plan last summer, he called the clean-fuels component "perhaps the most innovative and far-reaching" part of the package. Chief White House Counsel C. Boyden Gray leads the call to mandate the use of alternative fuels.

But a study published last year by Anthony Woodlief of the Competitive Enterprise Institute found that Bush's clean-fuels package would penalize consumers and could threaten public health. Woodlief contends that alternative fuels should be considered "clean" only when they significantly reduce all automotive pollutants. Yet among the favorites of the clean-fuel lobby are alternatives that tackle only a few pollutants and have a negligible effect on overall emissions. They are also more expensive to produce and reduce gasoline mileage.

Still, any fuel that lowers carbon monoxide and ozone formation, regardless of its impact on other emissions, usually earns the "clean" designation. These fuels take two forms: new formulations of gasoline and mixtures of gasoline with other fuels. The best-known substitute fuels are methanol and ethanol, oxygenated substances that need less air to combust than gasoline does.

Methanol is not quite the planet's best friend, however. Produced mainly from coal and natural gas, methanol is highly corrosive and highly toxic: A jigger or so would blind or perhaps kill you. Unlike gasoline, methanol is water soluble, so even a minor methanol spill could wipe out a city's drinking water supply. And while the use of methanol can reduce carbon monoxide and hydrocarbon pollution, producing methanol from coal causes more pollution than burning methanol eliminates. The fuel's corrosive properties also mean that methanol-fueled vehicles need corrosion-resistant equipment costing as much as $2,000.

A form of alcohol usually made from corn, ethanol attracts great interest in the Farm Belt. But like methanol, ethanol cuts some types of emissions while increasing others. A study released in May, authored by former ARB chief Thomas C. Austin, cast serious doubts on ethanol's value. Austin concluded that the standard "gasohol" mix of 10 percent ethanol/90 percent gasoline could cut carbon monoxide emissions by 25 percent but that hydrocarbons would rise as much as 50 percent and nitrous oxides as much as 15 percent.

Moreover, ethanol is not economically viable. It receives a 60-cent-per-gallon federal subsidy and numerous other tax breaks to encourage its production. Since gasohol is more expensive to produce than regular gasoline, Austin said, "motorists will end up paying more for dirtier air."

Ethanol's benefits to elected officials, however, are unquestioned. Archer-Daniels-Midland Co., chief sponsor of "This Week With David Brinkley" and other Sunday public-affairs shows, produces nearly three-quarters of the nation's ethanol and hands out tens of thousands of dollars in strategic political contributions. ADM receives more than a billion dollars in federal subsidies and other indirect government favors each year. In early May, Senate Minority Leader Bob Dole of Kansas introduced an amendment to the Clean Air Act that would mandate ethanol use in the nine smoggiest U.S. cities by 1994. A Wall Street Journal editorial reported that the ADM Foundation had recently given $160,000 to Dole's family foundation.

Some dedicated environmentalists recognize that oxygenated fuels have been oversold. A sympathetic article in the January 1990 Consumer Reports analyzing alternative fuels admitted that "oxygenates decrease the release of carbon monoxide [but] can increase smog formation. [They] make most sense in areas with carbon-monoxide problems but little smog." Clean fuels may soon be required, but while they will increase fuel prices, they will have little impact in places like Los Angeles and Milwaukee.

So do alternative fuels have any use? Reformulated gasoline looks promising. Last fall, Atlantic Richfield Co. introduced EC-1 to replace its regular leaded gasoline in California. Company officials say that substituting EC-1 for leaded fuel in pre-1975 cars would reduce volatile organic compounds by about 15 percent in the Los Angeles Basin. Last spring, Shell began offering a premium unleaded gasoline that reduces emissions from gas fumes. While these formulas do cost a few cents more per gallon to produce, state officials and representatives from environmental groups have praised them.

Other alternatives to gasoline as a motor fuel include electricity, natural gas, and hydrogen. But few working models or fuel-distribution sites exist. Without huge investments to manufacture vehicles and facilities, reformulated gasoline seems the best bet to become the "clean" fuel of the 1990s.

What effect would clean fuels have on auto pollution? Stedman says that if a car runs dirty because of mechanical failure, no formulation of fuel will clean it up. "The federal government's own data base [recommending clean fuels] shows that tuning up a few dirty cars would be twice as effective as oxygenating the whole fleet," he says. In a February Wall Street Journal op-ed, Stedman reported that the EPA tested 84 cars for its clean-fuels project; four dirty cars caused 85 percent of their pollution. Simply tuning those four cars reduced overall carbon monoxide emissions by 80 percent without using any oxygenated fuels.

Buyback programs pay owners to retire older cars. Union Oil of California (Unocal) recently introduced a program in California that would pay 7,000 drivers $700 each for pre-1971 cars. These programs, while good public-relations tools, have only minor environmental impact. Bill Sessa, a spokesman for the ARB, calls Unocal's program "a modest but welcome contribution," but no substitute for developing cleaner fuels. The Natural Resources Defense Council, the Coalition for Clean Air, and other environmental groups have responded similarly.

The Auto Club's Ortner isn't too keen on the Unocal buyback program. "Pre-'71 cars aren't the problem," he says. "When the equipment fails on the 1975–79 model cars, they pollute worse than older cars." Stedman is even more skeptical about the program. He says the EPA computer model for estimating auto pollution "assumes that every '71 car is dirtier than every '72 car, and so on. There's no evidence that '71 and older cars are any dirtier than '75. None."

EPA-approved tailpipe tests are the teeth enforcing air-quality standards in the 35 states with emissions-certification programs. But they have little bite. For one thing, states require them infrequently. Even in Los Angeles, the dirtiest American city, cars must pass smog tests only once every two years. An initially clean car that later falls short of the standard (for whatever reason) can pollute for months without being identified. California officials conduct random roadside emissions tests—but only to collect data, not to punish illegal polluters.

Furthermore, current EPA-approved smog tests are inaccurate and too easy to pass. The standard tailpipe test to measure idling cars "is probably one of the easiest tests in the world to pass," says biochemist Gary Bishop. "Having a car pass at idle may have nothing at all to do with how that car performs on the road." He contends that marginally functioning emissions-control equipment that doesn't work on the highway can still get by most idle tests.

Finally, while 1 in 10 cars causes most pollution, everyone has to put up with the inconvenience—time and trouble—of taking the standard smog test. "The pollution-control standards assume that drivers are guilty until proved innocent," Stedman says. "That's not the way it's supposed to work."

Mobile on-road pollution checks, however, are a nightmare for regulators: They work, they're cheap, and they don't require an enormous bureaucracy to administer. New technologies offer a chance to solve once-insurmountable problems, a scary prospect for regulatory agencies that want to expand their fiefdoms. Kent Jeffreys, a policy analyst for the Heritage Foundation who studies environmental issues, says regulatory agencies conform to the standard public-choice formula: "If they solve the problem, then they're out of a job."

Larry Arnn, president of the Claremont Institute and adviser to California's South Coast Air Quality Management District (AQMD), suggests that environmental regulators have become little more than central planners. "The AQMD constantly says it's a friend of business," Arnn says, "because it comes up with recommendations that are not only better for the environment but also are cheaper processes that produce better products. The AQMD actually believes it can allocate capital more efficiently than the market can. It becomes very easy for them to believe there should be no limits on their power." Decentralized, simple alternatives such as mobile testing would reduce agency power.

Officially, the ARB is committed to biennial smog tests, clean fuels, and stricter standards for future cars. Responding to the suggestion that there might be other ways to control auto emissions, ARB spokesman Bill Sessa asserts: "Our programs are accepted nationally. Mobile testing isn't a substitute for what we do now. There is no controversy about these issues." Well, there is a controversy, and it's being aired inside the ARB. A study of Stedman's methods commissioned by the board is scheduled to be published this summer. Stedman says an ARB "gag order" forbids him to discuss the results of the study before publication. Sources say the study reinforces earlier findings by the Denver researchers that the ARB would rather not air.

It's also tough to talk to the people who actually conduct research for the ARB. An ARB department head says the board discourages staff members from talking to the press. Department heads will grant interviews, but only with clearance from the public relations department. (In other words, if the ARB thinks you're hostile, you can't get past the PR department.)

Stedman also contends the EPA is frantic to delete a reference to mobile on-road emissions tests from the Clean Air Act. The agency is worried about ceding power to the states, he says. "Allowing mobile on-road testing would give state authorities more accurate information. It would also make them think about how they can clean up dirty cars. There's nothing in the enabling legislation of the EPA that requires [it] to think. Regulate, yes; think, no."

The version of the Clean Air Act passed by the House of Representatives mentions mobile on-road testing; the Senate bill doesn't. "One eight-word phrase will do more to clean the atmosphere than the rest of that 700-page document," Stedman says. "But it may not survive the [House-Senate] conference."

Auto industry officials warn that we may be reaching the design limits on clean, fuel-efficient engines. During the past two decades, technological improvements have greatly increased safety and fuel economy, but that same technology makes cars more expensive. As a result, the auto fleet is getting older: In 1975, the average age of a car in the United States was 6 years; now, it's 7.6 years. Many drivers can't afford to take advantage of the benefits new technologies provide.

Turf wars between bureaucrats and research scientists threaten to impede the development of effective pollution control. But simple and elegant systems like mobile emissions testing divide people who want to solve problems from those who would rather carve out bigger chunks of authority. Stedman laughs about these internal squabbles. "I can polarize more people against their own departments than you can possibly imagine," he chuckles. "It's an incredible talent."

Rick Henderson is researcher/reporter for REASON.