UC Irvine Institute of Transportation Studies

This paper investigates the cost-effectiveness of three strategies for reducing particulate and sulfur-oxide emissions from diesel transit buses. The strategies, in order of increasing effectiveness, involve low-aromatic fuel, particulate traps, and methanol fuel. All three are evaluated under optimistic assumptions. Three alternate indices of emissions are considered: one equal to total particulates (including those formed in the atmosphere from emitted sulfur dioxide); one based on California's ambient air quality standards; and one based on statistically estimated effects on mortality. At the fuel prices considered most likely, methanol is far more costly than other strategies per unit reduction in total particulates; but this disadvantage is greatly reduced using the other indices. In addition, methanol achieves the greatest absolute emissions reduction. With the mortality based index, the incremental cost of the methanol strategy over particulate traps in the Los Angeles basin comes to $1.6 million per incremental reduction in expected deaths.