中文摘要：

国内特大城市纷纷采取多中心空间战略来缓解单中心蔓延带来的城市问题，但是否有效却缺乏系统严谨的检验。从国内外大城市实施多中心战略的效果来看，各方评价褒贬不一，发达国家关于多中心结构能否缓解城市交通拥堵的实证研究更是对多中心理念的绩效提出了质疑。现通过对上海的实证研究来检验多中心理念的有效性，为我国特大城市多中心战略提供决策依据。运用统计方法和问卷调查数据对上海中心城区的分析显示，就业中心距主中心越远，其就业者的平均通勤时耗越低，因而强化多中心结构有助于降低整体通勤时耗；外围地区交通路况宽松和小汽车通勤比率高是多中心结构降低通勤时耗的主要机制，职住平衡在理论上应该是多中心结构降低通勤的机制之一，但在上海案例中没有呈现出随多中心强化而提高的态势。改善上海交通，应该塑造和强化多中心的空间结构，促进职住平衡和提高外围就业中心交通可达性是重要保障措施。

英文摘要：

Although polycentric spatial strategy is applied both in Chinese and foreign cities to address urban transportation problems caused by monocentricity, the effectiveness of such a strategy has not been well examined. The outcomes of implementing polycentric strategy are different from one case to another. Some scholars even cast doubt on the performance of polycentric strategy based on empirical studies in some developed countries. Therefore, an empirical research on of the effectiveness of polycentric urban structure in Shanghai is carried out to provide deeper insights into the issue. Statistical tests and questionnaire surveys are used to analyze the situation of Shanghai central city in this paper. The results indicate that the average commuting time of an employment sub-center is negatively correlated with its distance from the primary center, therefore, strengthening polycentricity helps the reduction of average commuting time in the whole region. In addition, the decline of commuting time in sub-centers can be attributed to better road condition and highly proportion of car usage for commuting purposes. However, jobs-housing balance has no positive effect on commuting time reduction although theories tend to argue otherwise. To improve Shanghai＇s transportation, it is advisable to form and strengthen the polycentric urban structure and enhance jobs-housing balance and the accessibility of employment sub-centers.