According to the Mexico City Metropolitan Area (MCMA) authorities the transport sector causes 75% of total pollutant emissions to the atmosphere, that is why to mitigate pollution several programs focus on reducing emissions from mobile sources, one of these programs promotes the use of Natural Gas (NG) in vehicles of the MCMA instead of gasoline or diesel. This work shows the cost-benefit analysis results of this program. The analysis considered the period 1999-2014. Projections for the MCMA vehicular fleet, and for the type and number of vehicles that would switch from gasoline or diesel to NG were made. To obtain the change in exhaust emissions, measurements were performed using the US Federal Test Procedure 75 in vehicles consuming gasoline and HG. Vehicle conversion, conversion shops, and gas station costs were considered in the analysis. The estimated benefits stemmed from fuel price and efficiency differential, vehicle taxes, maintenance costs, and pollutant emission reductions. The Benefit/Cost ratio found was 3.79, and the vehicles suggested for conversion were those of intensive use circulating exclusively in the MCMA. Even though ozone formation simulations were done using the CIT trajectory model, the changes in ozone concentrations observed were smaller than the model resolution, mainly because the change in ozone precursors due to the fuel change in some of the MCMA vehicles, was less than 1% of total emissions. (A)
Abstract