ON-ROAD CARBON MONOXIDE AND HYDROCARBON REMOTE SENSING IN THE CHICAGO AREA

Abstract

A carbon monoxide (C) and hydrocarbon (HC) infra-red remote sensor was utilized for measuring Chicago-area motor vehicle emissions. This on-road measuring system also recorded vehicle speed, an estimate of acceleration and a freeze-frame video of each vehicle's license plate. Exhaust %CO and %HC were calculated and are equivalent to tailpipe probe measurements. Grams of CO or HC per gallon of gasoline were measured in seven days. Half of HC was emitted by 14.25% with %HC greater than 0.23%. Half of the CO emitted came from 9.4% of those vehicles with %CO greater than 3.5%. Only a small fraction (20%) of all vehicles was responsible for most emissions. Most new vehicles are clear with regard to CO emissions, but %HC showed only a slight model year dependence. The dirtiest 20% of year-old vehicles had greater emission than the cleanest 20% of all vehicles regardless of age and emissions control technology. The average measurement for CO was 1.10% (425 gm/gal), and for HC, 0.139% (84 gm/gal) in propane equivalents). Implications for effective control strategies are outlined.