采用较小的曲线半径，能使线路更好的适应地形，绕避可能的障碍物，降低线路的桥隧占比，从而降低线路的建设费用。
A smaller value of radius can make lines adapt to topography better , bypass possible barrier , reduce the ratio of bridges and tunnels in lines . Consequently , the construction expenses can be reduced .
桥隧比