Soot-Free Urban Bus Fleets


Soot Free Buses


Urban buses around the world account for 25 percent of black carbon emissions from all passenger and commercial goods transport vehicles in 2015. The Climate and Clean Air Coalition’s (CCAC) Heavy-Duty Diesel Initiative (HDDI) aims to accelerate the transition of diesel urban bus fleets towards soot-free engine technologies. The core activity of this project is to directly inform, motivate, secure, and support the implementation of official commitments to shift toward soot-free engines.


The project will provide support to define a public commitment to soot-free bus fleets, as well as implementation support to identify soot-free engine technologies and the fuels that enable them, procure new vehicles, identify financing, and overcome other implementation barriers. Additional activities will include: building a private sector partnership base in order to establish formal relationships with manufacturers of soot-free engines who can serve as a point of contact and technical resource to all cities, including those that have not made a commitment; developing a database of urban bus fleets in selected regions to report in greater detail on the size, emissions, and projected future impacts of urban buses; and pursuing cross-linkages with activities to mitigate emissions of short-lived climate pollutants.


International Council on Clean Transportation
UN Environment Programme
Centro Mario Molina Chile
C40 Cities Climate Leadership Group


Diesel bus fleets bring with them many climate and health impacts. A presentation on the Case for Soot-Free Urban Bus Fleets provides an overview of this impact, cost-effective strategies to nearly eliminate diesel soot from city bus fleets, as well as more details on the project and available support for cities.

Several cities are on the path to making strong soot-free bus commitments. They include:

Johannesburg: Journey to a Soot-Free JoBurg presentation by Vusie Sithole, MetroBus summarises current thinking in the city, and a technical paper prepared by ICCT to support the city outlines some options and next steps
Lagos: Soot-Free Urban Bus Fleets in Lagos presentation by Olukayode Taiwo, Lagos Metropolitan Area Transport Authority summarises key opportunities and challenges in Lagos
Santiago: Santiago has adopted Euro VI Buses. Read the Case Study that provides a step-by-step view of how the Euro VI adoption happened.



  • Read the article by Gianni Lopez of Centro Mario Molina Chile on the importance of Euro VI buses published in the latest issue of Autobus, page 39 of issue 39. The magazine in Portuguese is published by the Brazilian bus industry and offers full information on the latest developments, including electric and natural gas buses and the latest on the BEV BYD chassis made in Brazil, news on a Volvo pilot of a new plug-in hybrid bus.


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