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Strategies for Mitigating Air Pollution in Mexico City - Media Release

In the middle of the pollution alert season, the International Transport Forum (ITF) at the OECD releases a new report with recommendations for mitigating air pollution in Mexico City and the extended metropolitan (ZMVM) and megalopolis area.

The recommendations are based on a review of Mexico City’s current strategies in the light of international best practice and a workshop with officials from London, Paris, Milan and Japan that took place in January 2017 in Mexico. The event was convened by the ITF-OECD and the Development Bank for Latin America (CAF) together with the Ministry of Environment of Mexico City (SEDEMA).

Updating of pollution alert limits in 2012, 2014 and 2016 for alignment with World Health Organization (WHO) guidelines revealed the full extent of the air pollution problem in Mexico City, with a series of ozone alerts in 2016 and 2017 as atmospheric concentrations exceeded health limits. On the basis of the workshop discussions between Mexican authorities and government officials from other major cities and international experts, the report sets out a comprehensive list of short and long-term actions that authorities in Mexico City, the surrounding States and the National Government can take to meet today’s air quality standards. 

The report includes the following recommendations:

  • Consolidate the use of on-board diagnostic system checks in the mandatory vehicle inspection and maintenance programme: On-board diagnostic (OBD) system checks are an important tool in the emissions testing procedure under the mandatory vehicle test, inspection and maintenance programme in Mexico City together with tailpipe exhaust gas testing. Both tests are required because of the greater effectiveness of OBD interrogation in detecting deficiencies, diagnosing faults and avoiding fraud, whilst dynamic tailpipe exhaust testing will catch problems invisible to OBD checks, ensure that emissions are within the current limits and also provides the default test for those vehicles that do not comply with current OBD requirements or are not equipped with OBD; of course only vehicles equipped with OBD should be eligible for certification in the cleanest vehicle categories.

  • Improve the mandatory vehicle inspection programme to include mechanical roadworthiness checks and to measure ultrafine particulate emissions: the condition of tyres, clutches, brakes and other mechanical components is important for both emission controls and safety. Including mechanical checks in mandatory vehicle inspections will create a maintenance culture that will improve air quality. Measurements of particulate numbers should be included in tailpipe exhaust gas testing in anticipation of future vehicle emissions regulations and to monitor the impact of gasoline direct injection technologies on the severity of particulate matter pollution.

  • Adopt state-of-the-art emissions standards for heavy duty diesel vehicles without delay: Mexico City incentivises the use of the latest generation of trucks and buses by exempting them from the restrictions on use introduced to manage air pollution. Nationally it has been decided to adopt the latest US and European (Euro VI) standards but the timetable has still to be agreed. These standards should be adopted for all new vehicles without delay and without intermediate steps because of the major cut in emissions they are expected to deliver in real world driving conditions.

  • Continuously update the Hoy no circula driving restriction system in the Metropolitan Zone of the Valle de Mexico and improve enforcement: Further differentiation of restrictions on the use of vehicles should be introduced to incentivise purchase of cleaner light duty vehicles. The latest light duty vehicle emissions standards (EPA Tier 3 / Euro 6) should be used as reference values ahead of their incorporation in national standards. Reciprocal arrangements for enforcement and collection of fines for contravening restrictions should be agreed between the States participating in the Environmental Commission for the Megalopolis (CAMe).

  • Phase in a city-wide low emissions zone: The current Hoy no circula system could be complemented, and perhaps replaced in the long term, by a city-wide low emissions zone, using the existing vehicle inspection, classification and identification system. Preparations for introduction of a low emission zone are recommended, with studies to examine practical implementation issues. The initial focus would be control of freight vehicles.

  • Manage parking more effectively and consider road pricing: Extending charges for on-street parking throughout the ZMVM is an important step. Moving from fixed to differentiated parking rates will be necessary to better reflect the value of public space in different areas and incentivise modal shift in areas that are well served by public transport. Removing regulations that require minimum parking spaces to be provided in new buildings is also an important step. Specific mechanisms to reduce congestion are also needed. The more widespread use of on-road parking charges is an effective tool for this together with road pricing and congestion charges and their potential for practical implementation should be evaluated.

  • Reduce speeds on motorways and ring roads: Speed limits produce immediate reductions in emissions at very little cost. The 80 km/h speed limit on urban motorways and ring roads introduced in Mexico City in 2015 should be adopted across the Metropolitan Zone of the Valle de Mexico and enforced to ensure vehicles on highways operate more often in the 50 to 90 km/h range in which emissions control technologies work best.

  • Improve sustainable transport alternatives to cars and taxis: Measures to improve strategic planning and coordination of public transport services as set out in the PROAIRE programme should be pursued as a matter of high priority. This includes reform of bus concessions throughout the ZMVM. The programme of investments underway for extending the metro and BRT network and improving station access and protected walking and cycling infrastructure is an important part of the package and should be effectively delivered.

The report “Strategies for Mitigating Air Pollution in Mexico City: Best international practice” can be viewed online and downloaded from

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