Abstract:

Regarding the ramp design problem in the elevated road network, the ramp location always affects the network performance and whether there exists a design paradox. This paper investigates the ramp design problem by optimizing the ramp location and its capacity simultaneously. The ramp design paradox in urban elevated road network and its intrinsic reason are also discussed. A ramp design model is proposed as the bilevel programming considering the importance of ramp location for the elevated road network in a corridor. The design variables in the bilevel programming are ramp location, ramp capacity and ramp type. The design objective in upper level is to minimize the total travel cost in the network, and the traffic assignment in low level is user equilibrium problem. In the last section, numerical examples are conducted to demonstrate the merits of the proposed model. Meanwhile, some numerical results show that the proposed model guarantees promising effects.

Key words: urban traffic, ramp design, bilevel programming, elevated road, ramp location, paradox

摘要：

在高架道路匝道设计中，路网性能及设计悖论的出现与否都受匝道位置的影响，本文对同时优化匝道位置和通行能力的匝道设计问题进行了研究.通过分析设计中可能出现的悖论问题总结了导致其出现的原因.鉴于匝道位置的重要性，建立了考虑匝道位置的走廊通道高架道路匝道设计双层规划模型.模型的决策变量为匝道布设位置、通行能力以及类型(上/下高架)，上层目标为最小化网络的总出行时间，下层为交通分配问题.最后，通过计算示例来验证所提出模型的优点，算例结果表明,考虑匝道位置的优化设计模型能获得较好的效果.

关键词: 城市交通, 匝道设计, 双层规划, 高架道路, 匝道位置, 悖论