北京西单街景改造工程含三个部分 ,第一部分为九座天桥 ,其中三座跨越 70 m红线的西单北大街 ,一座跨越 5 0 m红线的辟才胡同 ,其余 6座分别位于西单北大街东西两侧。使西单北大街实现了规划中的二层步行系统 ;第二部分为一幢180 0 0 m2 商场 ,位于西单西侧商业区 4#地 ,东临西 Beijing Xidan streetscape reconstruction project has three parts, the first part of the nine flyovers, of which three 70m red line across the Xidan North Street, a red line across the Piedai alley, and the remaining six were located in Xidan North Street East and West two side. So that Xidan North Street to achieve the planned two-story walk system; the second part of a 180 0 0 m2 mall, located in Xidan west commercial area 4 #, east west