The invention relates to an overpass which is a crossroad three-layer overpass. The overpass is provided with sixteen lanes. The sixteen lanes comprise four straight lanes, four right turning lanes, four left turning lanes and four turning lanes. The overpass has three layers, and the ground of the first layer is not provided with lanes and only allows pedestrians to pass. And the second-layer bridge floor and the third-layer bridge floor are vehicle passing channels. And the second-layer bridge surface is rectangular. Six lanes in the south-north direction are arranged on the second-layer bridge floor, and from west to east, the lanes 10, 2, 11, 12, 1 and 9 are sequentially arranged on the second-layer bridge floor. And the third-layer bridge surface has a dodecagonal pattern. And six east-west lanes are arranged on the third-layer bridge floor. The number 11, the number 3, the number 9, the number 10, the number 4 and the number 12 are sequentially counted from north to south. The two north-south straight lanes, the four right turning lanes and the four turning lanes are arranged on the second-layer bridge floor in the whole process. And the two east-west straight lanes are arranged on the three-layer bridge floor in the whole course. And the turning parts of the four left turning lanes are arranged on the second-layer bridge floor.

本发明所述立交桥，为十字路口三层立交桥。立交桥设置十六条车道。十六条车道是：四条直行车道、四条右拐弯车道、四条左拐弯车道、四条调头车道。立交桥有三层，一层地面不设置车道，仅供行人通行。二层桥面和三层桥面为车辆通行通道。二层桥面为长方形。二层桥面上有六条南北走向车道，由西向东数依次是：10、2、11、12、1、9号车道。三层桥面是十二边形图案。三层桥面有六条东西走向车道。由北向南数，依次是：11、3、9、10、4、12号车道。两条南北向直行车道、四条右拐弯车道、四条调头车道全程在二层桥面。两条东西向直行车道全程在三层桥面。四条左拐弯车道的拐弯部位在二层桥面。