Less than 5 percent of all cars are responsible for most of the air pollution problems in the United States and their owners waste hundreds of dollars in gasoline cost by not keeping their cars well maintained. Are you one of them?
You can easily find out by driving your vehicle by the Smart Sign, a car emissions testing device developed by a research group at the University of Denver. The Smart Sign is located on the southbound I-25 exit onto Speer Boulevard (Exit 212A). It is coupled to a sensing system, which detects the amount of carbon monoxide (CO) and ozone-producing hydrocarbons emitted by the car.
Less than a second after driving past the sensing system, the Smart Sign gives a reading, which tells how fuel-efficient or “clean” the car is. Three different readings, “GOOD”, “FAIR” and “POOR,” correspond to less than 1 percent CO, between 1 and 3.5 percent CO and more than 3.5 percent CO, respectively.
Donald Stedman, professor at the Department of Chemistry and Biochemistry, developed the technology powering the Smart Sign. It is called remote sensing and is located underground.
The remote sensing system consists of a series of mirrors that direct light coming from a source located on one side of the road to a detector located on the other side. The beam of light crosses the path of the car’s exhaust. Pollutants like carbon monoxide absorb, or filter out, specific parts of the light.
The amount of light that is able to reach the detector on the other side of the road tells how much of each pollutant is present in the car’s emission. A computer analyzes the data obtained from a car and triggers the Smart Sign to give a reading.
Stedman hopes the Smart Sign helps raise public awareness about the importance of a well-maintained car more effectively than required emissions tests would.
“What if we all had to take a breathalyzer every two years in order to drive? Do you think that would stop drunk driving? Probably not,” said Stedman, “Do you think that mandatory emissions testing does much for keeping the air clean? I don’t think so.”
The few cars that generate the vast majority of air pollution either lack air pollution control devices or have devices that don’t function properly.
The Smart Sign provides a way to self-monitor the emissions status of a car without having to bring the car in for a costly and time-consuming emissions test.
Stedman’s group has been working on the development of remote sensing devices to measure car exhaust since 1987 and has used its technology to collect emissions data in 21 countries around the world and in more than 25 U.S. locations.
So far, the technology can only be employed on single-lane roads. But Stedman hopes to be able to measure cars driving on multi-lane roads in the future.
“We have the ideas for multi-lane work,” he said. “We just don’t have the funding yet.”
Visit the Smart Sign’s home page at http://www.sign.du.edu/
