中文摘要：

以1986、1994、2005年为时间断面,加权平均旅行时间为指标,长三角地区20世纪80年代以来综合交通网络及其可达性的时空演化呈现如下特征：①综合交通网络的快速发展带来了综合交通可达性的不断提升,且第二阶段（1994-2005）发展速度明显快于第一阶段（1986-1994）;三时间断面上海及环太湖地区均为可达性最优区域,1986及1994年可达性较优区域大致由沪宁沿线和沪杭沿线构成＂〉＂形,而2005则大致由沪宁沿线（含沿江地区）、沪杭沿线及杭甬沿线构成＂Z＂形;②可达性提升中节点获益具有明显区域差异,加权平均旅行时间初始值越高的节点其值下降幅度越大,加权平均旅行时间的变化率中部地区低于南北边缘地区,但变化值及变化率在不同阶段均呈现不同特征;③从分省市角度,上海可达性最优,江苏板块次之,浙江板块较差,但上海的优势地位逐步下降,浙江板块与江苏板块间的差距正不断缩小;④综合交通可达性系数标准方差逐步下降,表明长三角地区综合交通网络发育日益成熟,但不同交通方式具有不同发展特征。

英文摘要：

Based on the integrated transport network in 1986,1994 and 2005,choosing weighted mean travel time as the indicator,the temporal and spatial evolution of integrated transport network and its accessibility are elaborated,and some conclusions are drawn as follows.（1） The speedy development of integrated transport net-work results in the continual improvement of accessibility,which is faster in the second period（1994-2005） than that in the first period（1986-1994）.The optimal region of integrated accessibility is Shanghai and the zone along the Taihu Lake in three time section.The sub-optimal region of integrated accessibility was ＂-shaped＂ that consisted of the zone along the Shanghai-Nanjing route and the Shanghai-Hangzhou route in 1986 and 1994,but it had the ＂Z-shaped＂ pattern that consisted of the zone along the Shanghai-Nanjing route,the Yangtze River and the Shanghai-Hangzhou route,and the Hangzhou-Ningbo route.（2） The benefits from the improvement of accessibility are different among the nodes.The changing extent of weighted mean travel time is related to the initial value,and the nodes with high initial value decrease more.The changing rate is higher in the central region than that in the north and south regions.Both the changing extent and the changing rate have different patterns in the different periods.（3） Shanghai has the best in integrated accessibility,followed by Jiangsu provinces,and Zhejiang province is the worst,but the dominant position of Shanghai is weakening,and the gap between Jiangsu and Zhejiang is narrowing.（4） The standard deviation of integrated accessibility coeffi-cient decreases in the research period,which shows that the integrated transport network in the Yangtze River Delta is improving,but there are different developmental processes among various transport modes.