The first cause is the great increase in the number of private cars.Cars take up more space but they carry fewer people.Some private car drivers,ignoring1 traffic regulations,drive only for the sake of their own convenience,blocking the way of other public transportation vehicles.The second cause is the slow and inefficient2 construction and improvement of the roads and streets.With a large population and numbers of automobiles increasing,some roads still remain unimproved,which will surely lead to problems.The last cause is the people’s disobeying the traffic rules.Many people cross the streets even when the traffic lights are against them,which causes the slow flow of traffic. Then how to solve this problem?I think the best way to solve the traffic problem is that more roads should be built to hold more traffic and at the same time more public bus routes can be opened up to those who prefer to use the public transportation.