The event, organised by non-profit group Action for the City, aims to raise public awareness of air pollution caused by vehicles and encourage more people to take public transport or ride a bicycle. The day had received a lot of support from the inhabitants in the city, especially university students.

The initiative received an award during the World Bank’s Vietnam Innovation Day 2007, as well as funding from the Swiss Agency for Development and Cooperation.

Action for the City was first set up under the Vietnam Union of Science and Technology Association and approved by the Ministry of Science and Technology on January 12, 2007. Its mission is to improve the quality of life for all people in Hanoi and other cities by increasing community participation and advocating green policies.