Overall, GHG emissions from road transport increased by 4.9 per cent compared with 1988 levels: 7,169.5 Gg C02eq. However, growth from 1991 to 2011 is calculated at 114.1 per cent. The most significant contributor to GHG emissions is passenger cars, followed by heavy-duty vehicles, light-duty vehicles and motorcycles and mopeds. As can be observed in figure 5.5, in 2011, passenger cars and heavy-duty vehicles accounted for 61.7 per cent and 19.9 per cent of total GHG CCheq.