汉朝是中国历史上最重要的朝代之一。汉朝统治期间有很多显著的成就，它最先向其他文化敞开了大门，对外贸易兴旺。汉朝开拓的丝绸之路通向中西亚乃至罗马，各类艺术流派繁荣，涌现了很多文学，历史，哲学巨著。公元100年中国第一部字典编纂完成，9000个字，提供释义并列举不同写法。其间，科技方面进步也取得了很大进步。发明了纸张，日晷以及测量地震的仪器，汉朝历经400年，但统治者的腐败最终导致了它的灭亡。

　　Han Dynasty enjoys a high level of significance in Chinese history during which lots of achievements and accomplishments have been made. It is a pioneer in terms of embracing other cultures and prosperity in foreign trade. The Silk Road which was opened at that time, led the way to the Middle and Western Asia and even to Rome, where a great number of literature, historical and philosophical masterpieces were springing up and all kinds of schools of art were flourishing as well. In 100 B.C., the compilation of China’s first dictionary was finished with explanation and ways of writing of 9000 characters contained. Meanwhile, with the invention of paper, water clock, sundials and the instruments used to measure earthquakes, the great progress has been made in scientific development. The Han Dynasty lasted for 400 years. However it finally ended up due to the corruption of the rulers。

　　2011年是中国城市化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张，并把大量投资转向安全、清洁和经济型交通系统的发展上。

　　The year of 2011 is regarded as a historical moment in the process of Chinese urbanization, when the population in urban area has surpassed that in rural place for the first time. There is a prediction that about 350 million people will move into the urban area in the next 20 years. The development of city on such a scale brings both opportunities and challenges to its transportation. The Chinese government has advocated for the people-oriented development for a long time, emphasizing that people should go out by public transportation rather than private ones. At the same time, the construction of a resource-saving and environment-friendly society is also what the government is appealing to. With such a target, we could plan the urban construction and development in a more reasonable way and much investment could be transferred into the improvement in a transportation system, which is secure, less polluting and economic。