The invention relates to an overpass, in particular to a crossroad double-bayonet-wrench-shaped three-layer overpass. The overpass is located at a crossroad. The first-layer ground of the overpass is not provided with lanes and only allows pedestrians to pass through. And the second-layer bridge floor and the third-layer bridge floor are vehicle passing channels. The overpass is provided with four straight lanes, four right turning lanes, four left turning lanes and four turning lanes. And the second-layer bridge surface is rectangular. Six north-south lanes are arranged on the second-layer bridge floor, and the six north-south lanes are sequentially 2, 10, 11, 12, 9 and 1 lanes from west to east. The three-layer bridge surface of the flyover is in the shape of a double-bayonet wrench. Six east-west lanes are arranged on the third-layer bridge floor, and the six east-west lanes are sequentially No.11, No.9, No.3, No.4, No.10 and No.12 lanes from north to south. The two north-south straight lanes, the four right turning lanes and the four U-turn lanes of the overpass are arranged on the second-layer bridge floor in the whole course. And the two east-west straight lanes are arranged on the three-layer bridge floor in the whole course. The four left turning lanes of the flyover pass through the second-layer bridge floor and the third-layer bridge floor.

本发明所述立交桥，为十字路口双卡口扳手形状三层立交桥。立交桥位于十字路口。立交桥的一层地面未设置车道，仅供行人通行。二层桥面和三层桥面为车辆通行通道。立交桥设置四条直行车道、四条右拐弯车道、四条左拐弯车道、四条调头车道。二层桥面为长方形。二层桥面上有六条南北向车道，由西向东数，依次是：2、10、11、12、9、1号车道。立交桥三层桥面的形状是双卡口扳手形状。三层桥面上有六条东西向车道，由北向南数，依次是：11、9、3、4、10、12号车道。立交桥的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。立交桥的四条左拐弯车道既经由二层桥面又经由三层桥面。