题目：In cities and towns all over the world the high volume of traffic is a problem. What are the causes of this and what actions can be taken to solve this problem?
开头段：背景引入 + 话题介绍。
背景句：It is undoubtedly the case that urban areas around the world increasingly suffer from congestion.
话题介绍：In this essay, I examine the reasons for this trend and suggest some practical policies the authorities could implement to reduce the level of traffic in our cities.
主题句：The first step is to understand why traffic has increased in towns and cities. Broadly speaking, there are three main reasons for this.
平行列举：One is that cars have become more affordable for the average consumer and they are no longer a luxury item, but something that most families expect to own. A second reason is that public transport has become increasingly unreliable in recent years, not least because many bus and train services have been reduced because of the difficulty in funding them. The third reason is that society has in general become more mobile and this means more people are prepared to commute to work by car than they were before.
提出对策：There is almost certainly no one solution to this problem given the complexity of its causes. However, one option has to be to improve the reliability of public transport to encourage people to take the bus or the train rather than get in the car. It would also be possible to discourage people from driving to work by introducing special tariffs for using the roads, especially during peak periods.
举例：A successful example of this is the congestion charge scheme in London which has certainly reduced the level of traffic in inner-city areas.
In conclusion, there are a variety of different factors that have led to rising levels of traffic in urban areas. While it may not be possible to find a complete solution, any action should probably involve encouraging greater use of public transport and making it more expensive for the motorist to drive in urban areas.
It is undoubtedly that… 毫无疑问，……
Broadly speaking, there are + 数字 + reasons for sth. 普遍来说，造成某事的原因有几个。
A become affordable for B. B 能够买得起 A。
There is no solution to A because of the complexity of B. 由于 B 的复杂性，没有解决 A 的方案。
There are a variety of different factors that have led to A. 有很多不同的原因导致 A。