前言上海人口众多,近几年来车辆猛增,而市区道路的改造和建设又跟不上交通的迅速发展,因而在市区商业繁华的交通干道上,车辆拥挤,经常阻塞、车速逐年下降,行人穿越马路,提心吊胆,人车混杂,事故不断增加。虽然早在1955年就兴建了大统路跨铁路人行天桥,但作为改善城市交通的对策而特 Foreword Shanghai has a large population and the number of vehicles has soared in recent years. However, the renovation and construction of urban roads can not keep up with the rapid development of transportation. Therefore, crowded and often obstructed vehicles and declining speeds have been seen in urban commercial and prosperous traffic routes. Pedestrians crossing the road, scared, mixed people and vehicles, accidents continue to increase. Although Datong Road cross-rail pedestrian bridge was constructed as early as 1955, as a countermeasure to improve urban transport,