The Sustainable Urban Transport Project (SUTP) Asia is a partnership between the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ), the Bangkok Metropolitan Administration (BMA), CITYNET and the United Nations Economic and Social Commission for Asia and the Pacific (UNESCAP). It aims to help developing world cities achieve their sustainable transport goals, through the dissemination of information about international experience, policy advice, training and capacity building and targeted work on sustainable transport projects within cities.
Bogotá is well known for several of its transport projects and initiatives. One of them is its 12-year old carfree day, which was first implemented in 2000 as a mandatory 14-hour ban on automobiles to promote the use of other travel modes and as a positive the reflection to support sustainable transport modes. The day was observed on the first Thursday of February every year.
3 February, 2011 was the 13th example of this event (2003 had it twice by decree as well, the second one being held in September 22 as it is done in other parts of the world). From the year 2007, it had changed its official name from "carfree day" to "Day for the Clean Air", and its focus shifted from one strictly related to car restrictions to one more on air quality in general.This shift from restrictions to air quality has had various reasons and impacts. For one, it has shifted the bulk of the administrative and promotional work to the Environment Department from the Mobility Department, leaving the latter with fewer responsibilities and thus with little work on "how people must move" during carfree day.
The Environment Department focussed its work on promoting cleaner diesel fuel for public transport (almost exclusively), which brought one very good thing in 2009: the effective reduction of Sulfur content in all Diesel in Colombia, Bogotá being the city with lowest Sulfur content of all (50 ppm for mass transit vehicles such as TransMilenio's, 500 ppm for any other vehicles). As such, it has turned out to have a very positive outcome in that sense.