Comparison of 1995 and 1996 Emissions at the Los Angeles Sepulveda TunnelIncluding the Impact of California Phase 2 RFG

摘要

California faces some of the most serious air quality problems in the U.S., withmotor vehicles a leading source of ozone forming precursors, carbon monoxide, and other toxic species. One of the control measures designed to reduce mobile source emissions of these species was the introduction in mid-1996 of California Phase 2 Reformulated Gasoline (RFG). Compared with California Phase 1 RFG (introduced in January 1992) and California Transitional Gasoline (introduced in January 1995), California Phase 2 RFG was designed reduce even further emissions of hydrocarbons, oxides of nitrogen, carbon monoxide, and toxic species, among others. An opportunity to evaluate the impact of California Phase 2 RFG was presented by the completion in October 1995, prior to the introduction of the new fuel, of an experiment measuring on-road motor vehicle emissions in the Sepulveda Tunnel of Los Angeles. Results of the 1995 study provided a benchmark with which were compared to mid-1996 or later emissions measurements in order to determine the impact of California Phase 2 RFG on mobile source emissions.