Millions of people come to Shanghai adding to the existing population of the City; therefore public transport has to be enhanced. The City transports 15-million passengers daily. The number has risen to 16, 4- million with the Shanghai Expo currently being held. Subways are estimated to transport 5, 2-million people daily while buses transport 7, 8-million daily. Buses are regarded as a main transport mode; taxis supplement them while subways are regarded as the backbone of public transport.