Alternative transportation fuels and air quality

One method of reducing air pollution is the replacement of conventional vehicle fuels with alternatives, such as methanol, LPG, and reformulated gasoline. The 1990 Clean Air Act Amendments mandate the use of several alternative fuels. While alternative fuel use will probably help improve air quality, particularly in urban ozone reduction, it is possible that these improvements will not be very great. Among alternative carbon-based fuels compressed natural gas offers the best chance for improving urban air quality. The widespread use of electric cars and trucks would certainly result in substantial air quality improvements.