B喇叭形互通式立交环圈匝道出口线形优化设计

Optimal Design of Loop Ramp Exit Alignment of B Trumpet Interchange

大量的喇叭形互通式立交的安全调查分析表明,B喇叭形互通式立交的事故率高于A喇叭形互通式立交,其中左转出口环圈匝道是最大的安全隐患。如果增大环圈匝道的半径,会导致互通式立交的占地增大,从而增加了工程投资,并且行车的舒适性的改善并不明显,因此,B喇叭形互通式立交的安全设计仍是对环圈匝道的出口进行控制。目前,常规B喇叭形互通式立交环圈匝道的出口线形设计不满足分流鼻曲率半径和运行速度过渡的要求,为提高环圈匝道出口的行车安全水平,提出了一种卵形曲线的环圈匝道出口线形设计方式。

The safety investigation and analysis of a large number of trumpet shaped interchange shows that the accident rate of the B trumpet interchange is higher than that of the A trumpet interchange, the left loop exit ramp is the biggest security risk. If the radius of the loop ramp is increased, the area of the interchange will be increased, which will increase the investment of the project, and the improvement of driving comfort is not obvious. Therefore, the safety design of the B trumpet interchange is still to control the exit of the loop ramp. The current status of the conventional B trumpet interchange of the loop ramp exit line design does not meet the requirements of the radius of curvature in shunt nose and running speed transition, in order to improve the safety of the exit of the loop ramp, a new design method of the curve shape of the loop ramp exit is proposed.