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NARSTO Workshop on Innovative Methods for Emission Inventory Development and Evaluation University of Texas, Austin October 14-17, 2003 |
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Characteristics of the Monterrey Metropolitan Area Vehicle Fleet and Its Estimated Emissions
Gerardo Mejia, Francisco Obregón, Jorge Sánchez, and Jean-Benoit Daumerie
Center for Environmental Quality, ITESM, Monterrey, Mexico
Jedidiah Horne
Massachusetts Institute of Technology
Andrew Burnette
ERG, Austin, Texas
The vehicle feet in the Monterrey Metropolitan Area (MMA) has increased from 687,000 vehicles in the year 1995 to more than 1,100,000 in the year 2003. The pollutant concentrations in the air have exceeded the 24-hour air quality standard of 150 µg/m3 for PM10 several days of the year as well as the one-hour average of 0.11 ppm for ozone. Moreover, since air quality monitoring activities started in 1993, the annual average standard of 50 µg/m3 for PM10 has been exceeded in the MMA, except for the year of 1997. Feasible air pollution control strategies based on technical, eeconomic and political issues need to be implemented. However, a reliable and “up-to-date” emission inventory does not exist. The last emission inventory for the MMA was calculated in 1995. In this work we present the results of a study to characterize the vehicle fleet of the MMA and its emissions. The fraction of unregistered vehicles is considered in the mobile source emission inventory. This fraction was estimated during a recent study that compared the results of an on-road vehicle survey to the registration database. It includes non-registered, out-of-the-state and out-of–the-country vehicles. The emissions are estimated and compared using the MOBILE5 model adapted for the MMA and the MOBILE 6 model. A proposed pattern of spatial distribution of emissions is presented based on a study of vehicles sampled in different parts of the MMA. Recommendations are given to improve the data in the vehicle registration files and in the estimated emissions. The study and data presented is a foundation for the development of the MOBILE6 model for Mexican vehicles (MOBILE6-Mexico) and to improve the estimates of air pollutant emissions.