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Clean Cars Program Case Study

Denver, Colorado

Conventional wisdom holds that a relatively small percentage of the vehicles on the road account for a majority of the emissions. In 1993, the Regional Air Quality Council, the non-profit metropolitan planning agency for air quality in the Denver area, established a program designed to target these vehicles. With a $500,000 grant from Total Petroleum, Inc., an independent petroleum products refiner and marketer, the RAQC designed and administered a repair and retirement program on a voluntary basis.

The program focused on the repair or retirement of high-emitting vehicles in the Denver metropolitan area (which is nonattainment for CO, PM-10, and ozone). Eligible vehicles were identified by one of three means:

  1. Colorado's Inspection and Maintenance Program waiver list, consisting of vehicles that have not passed the emissions test but are allowed to stay on the road because repairs above a certain specified amount had been made;
  2. roadside remote sensing, using equipment leased from the University of Colorado; and
  3. the Denver and state smoking vehicle hotlines, which allow citizens to report vehicles emitting visible smoke.

Owners of the vehicles identified were solicited by mail to participate in either the repair or retirement aspect of the program. Owners invited to repair their vehicles were offered $500 toward the cost. If the cost of repairs exceeded $500, the owners could pay the excess over $500, retire their vehicles (in return for $1,000), or opt out of the program, receiving a courtesy oil and filter change.

Altogether, 218 vehicles were repaired to run more efficiently and cleanly over a five-month period, while 271 vehicles were retired. Emissions impacts were quantified by the Colorado Department of Public Health and the Environment. The program removed an estimated 205 tons of CO and 41 tons of VOCs.

Participants were contacted after the program, and all said that they were very satisfied and would participate in future programs if given the opportunity.

Model Rule

Because this was a voluntary program, no rule was necessary.

Quantification

Emissions were quantified using standard emission factors from inspection and maintenance programs.

Further Information

For further information on the Denver Clean Cars Program, contact Tymon Lodder, Regional Air Quality Council, 303 629-5813.

Similar Programs

The South Coast Air Quality Management District, in Los Angeles, California, operates a voluntary repair program. Contact Dave Coel, SCAQMD, 909 396-3143.

Several states and localities have operated vehicle scrappage programs. Here are two:

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