As of 2012[update], there are over 3.5 million vehicles operating in the city, of which 74% are two-wheelers, 15% cars and 3% three-wheelers. The remaining 8% include buses, goods vehicles and taxis. The large number of vehicles coupled with relatively low road coverage—roads occupy only 9.5% of the total city area:79—has led to widespread traffic congestion especially since 80% of passengers and 60% of freight are transported by road.:3 The Inner Ring Road, the Outer Ring Road, the Hyderabad Elevated Expressway, the longest flyover in India, and various interchanges, overpasses and underpasses were built to ease the congestion. Maximum speed limits within the city are 50 km/h (31 mph) for two-wheelers and cars, 35 km/h (22 mph) for auto rickshaws and 40 km/h (25 mph) for light commercial vehicles and buses.