Evaluation of the Vehicle Inspection/Maintenance Program in the Metropolitan Area of Mexico City

• Published in: Environmental science & technology Vol. 37; no. 1; pp. 196 - 200
• Main Authors: Schifter, I, Díaz, L, Vera, M, Guzmán, E, Durán, J, Ramos, F, López-Salinas, E
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-01-2003
• Subjects: Air Pollutants - analysis; Air Pollution - prevention & control; Applied sciences; Atmospheric pollution; Certification; Cities; Emissions; Engineering; Exact sciences and technology; Humans; Inspections; Metropolitan areas; Mexico; Motor Vehicles - standards; Pollution; Pollution sources. Measurement results; Quality Control; Transports; Vehicle Emissions - analysis; Vehicle Emissions - prevention & control; Vehicles; Central America; Mexico; America; Mexico City Mexico; Mexico, Mexico City; Performance evaluation; Surveillance; Gasoline engine; Air pollution; Air quality; Exhaust gas; Road traffic; Motor vehicle; Urban area; Maintenance; Checking program; Pollutant emission
• DOI: 10.1021/es020549t
• EISSN: 1520-5851
• ISSN: 0013-936X

The Inspection/Maintenance Program in the Metropolitan Area of Mexico City (MAMC) mandates a test every 6 months for all gasoline motor vehicles as one of the strategies to decrease emissions of vehicular pollutants. FTP-75 and ASM procedures were performed in our facilities to a fleet of 108 in-use motor vehicles before and after the approval of the I/M mandatory test. When our laboratory-simulated ASM data were compared with those of the official certificate, a large difference was observed between them. On the other hand, audits at the test-only centers indicate poor maintenance of the analytical instruments and dynamometers. On the basis of our FTP results, an estimation of the emissions change for the MAMC fleet shows a net 4% decrease in CO emissions, while total hydrocarbons and NO x increased 9 and 8%, respectively. Our results indicate that the I/M system in the MAMC lacks the technical capability and investment to ensure that software and hardware are properly maintained, calibrated, and upgraded. Sometimes limited attention is paid to ensure adequate training of inspectors, auditors, and quality control staff.