Emissions from motor vehicles measured by remote sensingin Mexico City– 2005

摘要

We show the results of the campaign of remote sensing of automotive vehicles that circulated inthe Metropolitan Area of Mexico City MAMC from May 30 to July 14, 2005. The objectiveswere among others: To compare with the measurements of the I/M Program and to characterizethe emissions of the vehicles by type of use. We found a poor correlation between the twomeasurements and that many of the vehicles on the streets exceed the norm used in the I/Mprogram. The differences comes from: measurements in the I/M centers are in a vehicle at afixed speed and power averaged for 10 seconds, those on the street are made in a very short timeand may be in a cold catalytic converter. Vehicles on the I/M inspection are measured after amaintenance procedure, those on the streets are not. The remote sensor should not be used to finethe polluting vehicles, but could be used to exempt the clean vehicles from the I/M verification.Any vehicle with 3 or more clean measurements is really clean. We found that the light busesused in the public transportation emit from 2 to 4 times more contaminants than private cars,because most of them are without a catalytic converter.