中文摘要：

本文基于区域经济系统的开放性，以县域为研究单元，采用加权平均旅行时间指标，分析了长江三角洲区域公路、铁路、水运、航空等单方式交通可达性空间格局，并以此为基础剖析了区域综合交通可达性格局：公路交通可达性大致呈环状格局，铁路交通大部分节点可达性较好，台州市域南部节点和舟山可达性差，水运形成了弧状条带分布格局，航空可达性大致呈南北对称分布；综合交通可达性以上海及周边节点为中心向外围呈不规则环状逐渐降低，可达性较好区域大致构成“Z”字形。通过可达性系数分析，公路交通可达性分布较为均衡，综合交通和航空次之，水运较差，铁路最不均衡。文章的最后提出了区域交通可达性及其均衡性提高的针对性措施。

英文摘要：

Choosing weighted average travel times as indicator, county as research unit, this paper analyses the accessibility patterns of highway, railway, waterway and civil aviation respectively in the Yangtze River Delta under opening conditions, with these results, the accessibility patterns of integrated transportation are elaborated. The accessibility of highway takes on a layered pattern with Shanghai, Suzhou and Jiaxing as the center, which implicates the transport convenience of nodes within the region. Most nodes are better but those located in the south of Taizhou and Zhoushan （Zhejiang province） are worse in railway accessibility. In waterway transport, the accessibility shows an arc belt pattern, with better accessibility, in the center composed of Shanghai, Ningbo and Zhoushan, the belt along the Yangtze River in the north and along the East China Sea in the south but it decreases southwestwards and northwards （northeastwards）. The accessibility of civil aviation takes on a south-north symmetry pattern approximately, having nodes with better accessibility concentrated in the middle part. Shanghai is the best node in civil aviation accessibility, Hangzhou, Nanjing and Ningbo are better than those nodes around them, which form the ＂islands-shaped＂ pattern. As to integrated transportation, Shanghai and nodes around it are best in accessibility, centered around this area, the accessibility decreases to the periphery, and the area with better accessibility forms ＂Z-shaped＂ pattern, which is consistent with the regional transport and megalopolis pattern, and the accessibility of the nodes in the south and north edge are worse, as a whole, the north is better than the south and the east is better than the west in accessibility. According to the analysis of accessibility coefficient, the highway is the best one in equilibrium of accessibility distribution, integrated and civil aviation transportation takes the second place, waterway is worse, and railway is the worst. For the sake of integration of th