求翻译：为了平衡车行和步行，各个城市道路系统都在不断演变改造，以立交桥，过街天桥，地下通道为代表的立体交通逐渐增多。是什么意思？

In order to balance the car dealers and walking, all urban road systems are evolving transformation in order to overpass, overpasses, underpasses, represented by three-dimensional traffic gradually increased.

In order to strike a balance between the car and walk to the city road system is in constant evolution, and transformation in order to overpass, underpass, crossing the street flyover for representatives of three-dimensional traffic has increased.

In order to balance the car dealership and the walk, each urban road system all unceasingly is evolving the transformation, take the multi-level crossing bridge, the overpass, the underground channel increases gradually as representative's three-dimensional transport.

In order to balance the car and walk, each modification of urban road system are in constant evolution, bridge, footbridge, underground passage as the representative of the transportation on the rise.