2011年是中国城市化(urbanization)进程中的历史性时刻，其城市人口首次超过农村人口。在未来20年里，预计约有3．5亿农村人口将移居到城市。如此规模的城市发展对城市交通来说既是挑战，也是机遇。中国政府一直提倡“以人为本’’的发展理念，强调人们以公交而不是私家车出行。它还号召建设“资源节约和环境友好型”社会。有了这个明确的目标，中国城市就可以更好地规划其发展，并把大量投资转向安全、清洁和经济型交通系统的发展上。

[参考译文]

The 2011 is the historic moment in the process of Chinese urbanization, when the urban population surpassed the rural population for the first time. In the next 20 years, it’s estimated that about 350 million village people will move to cities. Such large scale of urbanization is both a challenge as well as a chance to the urban traffic. Chinese government has been advocating the development idea of “people-oriented”, stressing people should travel by bus rather than private cars. They also advocate building a “resources-saving and environment friendly” society. With this clear target, Chinese cities can better plan their development and divert more investment to the development of safe, clean and economical transportation system.

第一句后半句中的“其城市······”看似与前半句没有明显的逻辑关系，但是稍加分析就可以知道城市人口超过农村人口的时间也是2011年，所以用“when”连接即可。“以人为本”含有多种含义，概括地说就是发展以人为导向，因此翻译成“people-oriented”即可。“号召”也可以使用“call for”。全文出现了诸多专有名词，但是都可以用简洁的语言表达出来，并不难。