DESIGN OF ROBUST EMISSION REDUCTION STRATEGIES FOR ROAD-BASED PUBLIC TRANSPORTATION IN MEXICO CITY, MEXICO: MULTIATTRIBUTE TRADE-OFF ANALYSIS FOR METROPOLITAN AREA

Transportation-related air pollution is one of the major problems facing many megacities in developing as well as developed countries. The design of air quality strategies for the road-based public transportation system in the Mexico City metropolitan area (MCMA) is considered. An analysis is done of 28 different emission reduction strategies consisting of bundles of technological and supply and demand management emission reduction policies across alternative future development scenarios of the MCMA in the 2000-2025 period. The analysis combines demand modeling, fleet evolution modeling, mobile-source emissions modeling, and trade-off analysis to evaluate the impact of these emission reduction strategies and to determine their cost-effectiveness. The combined use of scenario analysis and multiattribute trade-off analysis is a unique approach that allows the design of strategies that are robust across a range of future uncertainties. Results of the analysis show that combinations of aggressive technological and supply and demand management strategies are needed to achieve sustained emission reductions in the 2000-2025 period. The recommendation calls for combinations of strategies that rely on aggressive hybrid vehicle introductions, catalyst and particulate matter and nitrogen oxide filter retrofitting, dedicated busways, public transportation fare integration, and subsidies and fuel taxes. These combined strategies can reduce transportation emissions by more than 85%. Results also indicate that even the most aggressive strategies fail to achieve sustained emission reductions in the case of urban sprawl and the rapid growth in transportation demand