Helps reduce air pollution and solve the fuel imbalance by implementing a "car-free day" The head of the Climate Change Center at the Environmental Protection Organization: implementing a car-free day and increasing the use of public transportation can help reduce air pollution and the fuel imbalance in the country. The transport fleet in cities such as Tehran and Shahid plays a dominant role in pollutant emissions. If we can reduce the use of private cars by about 10%, the rate of reduction of pollutant emissions from cars will be more than 10%.