• Since 2008, more than half of the world’s population lives in urban areas. In Europe, it's 60%.
• Urban transportation generates 40% of Europe’s carbon emissions from road transportation and 70% of related pollutants such as aromatic particles and unburned nitrogen oxides.
• The environmental cost of urban traffic in the European Community is estimated at 100 billion euros per year, including the cost of time lost in traffic jams, i.e. 1% of Europe’s GDP.

Source: European Commission Green Paper on urban transport.