再探交通网络超额需求容量模型与算法  

Revisiting excess demand capacity model and algorithm of traffic network

作　　者：彭茂珂 彭小东 黄俊 刘晓玲 丘建栋 谢军 PENG Maoke;PENG Xiaodong;HUANG Jun;LIU Xiaoling;QIU Jiandong;XIE Jun(School of Transportation and Logistics,Southwest Jiaotong University,Chengdu 611756,China;Southwest Municipal Engineering Design&Research Institute of China,Chengdu 610084,China;Shenzhen Urban Transport Planning Center Co.,Ltd.,Shenzhen 518000,China)

机构地区：[1]西南交通大学,交通运输与物流学院,成都611756 [2]中国市政工程西南设计研究总院有限公司,成都610084 [3]深圳市城市交通规划设计研究中心股份有限公司,深圳518000

出　　处：《交通运输工程与信息学报》2024年第4期128-141,153,共15页Journal of Transportation Engineering and Information

基　　金：国家自然科学基金项目(72371205)。

摘　　要：城市路网容量是指在路段容量限制下路网能够容纳的最大交通流量,是衡量城市供需平衡与指导政府投资方向的关键指标和重要依据。网络容量研究可以预测道路网络能够容纳多少额外需求,从而帮助管理者制定出切实有效的交通规划与管理政策。此类问题在数学上通常用一个双层优化模型来表述,上层模型的优化目标是最大化交通需求总量,下层则对出行者的路径选择行为和网络拥挤效应进行建模。但双层优化模型求解复杂且并不适用于大规模路网,大多双层模型在实际的应用中受到限制。因此,本文系统回顾了一种单层网络容量模型,即超额需求容量模型,并提出了一种高效的求解算法。算法的核心是利用基于路径的增广拉格朗日方法,多次求解一个考虑路段容量约束的用户均衡分配问题。数值实验结果表明,超额需求网络容量模型及其算法能够准确预测大规模城市交通网络在不同场景下的最大交通需求承载能力,为城市交通规划与管理提供有力的支持。在路网的承载极限状态下,某些流量已经达到或接近其容量的路段可能成为影响整个网络容量大小的瓶颈路段,可以据此为政府制定交通管控策略或道路改扩建投资提供依据,有望在实践中取得广泛应用。Urban-road network capacity,which is a key indicator for assessing the balance between urban-traffic supply and demand and a crucial decision-making basis for government investments,refers to the maximum traffic flow that a network can accommodate under the constraint of link capacity.Investigations into network capacity enables the prediction of additional demand that can be accommodated by a network,thereby assisting managers in formulating practical and effective trafficplanning and management policies.Mathematically,such issues are typically formulated as bi-level optimization models,with the upper-level model maximizing the total traffic demand and the lower-level model modeling traveler path-choice behavior and network-congestion effects.Because of the complexity of solving bi-level optimization models and their impracticality for large-scale networks,most of these bi-level models are limited in practical applications.This study systematically reviews a single-level network capacity model,namely the excess-demand network-capacity model,and proposes an efficient solution algorithm.This study introduces the concept of an augmented network to describe the capacity of a road network.The maximum network capacity is obtained by iteratively solving the traffic assignment for each fixed-demand problem.Numerical experimental results show that the excess-demand network-capacity model and its algorithm can accurately predict the maximum traffic-demand capacity of large-scale urban-traffic networks under different cases,thus providing a robust tool for urban-traffic planning and management.In scenarios where the road network is at its capacity limit,certain links whose volumes have reached or approached their capacity may become bottleneck links,thus affecting the overall network capacity.This information can be utilized to guide governmental decisions regarding traffic control strategies or road-expansion investments,thereby offering widespread practical applications.

关 键 词：城市交通 路网容量 交通分配 交通承载力 超额需求 

分 类 号：U121[交通运输工程]