大城市交通擁擠探因(the causes of traffic congesuon in big cities)
1．大城市普遍交通擁擠；
2．導致大城市交通擁擠的原因。
[寫作導航]第一段可作為介紹段，講交通擁擠很普遍，人們很關心並時有抱怨，因為給工作和生活帶來了不便；第二段可寫成轉折段，承上啟下，引起第三段講原因；三段集中講原因，可從私車增加、路況較差、管理水平不高、人們對交通法規意識淡薄等方面入手；第四段收尾。
[範文]
traffic congestion has long been a problem of great concern and complaint in big cities. it has caused a lot of inconvenience to people's life and work. for example, people have to set off well in advance to get to work on time and come back very late when their work is over.
there are many causes for this problem, but the following may be the most important ones.
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, ignoring 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 inefficient 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 insufficient management of the traffic system and the people's lack of awareness of traffic regulations. many pedestrians cross the streets even when the traffic lights are against them, which is an obstacle to the flow of traffic.
the problem of traffic congestion is an urgent one because it concerns the safety allofus. wewillnot resolve it if we only rely on the government. let all of us act now to solve it.