WARSAW, Sept. 22 (Xinhua) -- Warsaw and other major Polish cities made public transport available for free on Sunday on the occasion of the European car-free day.
In Warsaw, buses, trams and even some trains going outside the city were free on Sunday, as citizens were encouraged to use public transport instead of personal cars to promote ecological forms of transport public transport, biking and walking.
Other cities, such as Krakow in the south and Bialystok in the east, also took part in the action.
Cities also made available parking for free, so that people could leave their personal cars outside the city centers, and even cleared some central streets from traffic altogether.
In Warsaw, people could also take advantage of the car-free day to observe up close how a new metro line, expanding into the south-east of the city, is being constructed.
The car-free day is happening in Poland as people are gearing up for the cold season, when inhabitants of many towns in the country are negatively affected by smog.
According to the World Health Organization, 33 out of the most polluted 50 cities in the EU are located in Poland. It is estimated that between 45,000 and 50,000 people die yearly in Poland because of conditions caused by smog and air pollution.
The main culprits are thought to be coal-based household heating and transport.