已知起点需求和部分路段流量的交通OD反推模型及算法

Model and Algorithm of OD Demand Estimation with Given Traffic Generation Quantities at Origins and Partial Observed Link Flows

针对起点交通需求给定和部分路段流量可观测的情景,建立了交通OD量反推的双层规划模型。上层模型以最小化路段分配流量与观测流量之间的差异为目标。为了合理描述出行者的出行路线选择行为,下层模型采用了用户均衡交通分配模型。通过在增广拉格朗日乘子算法中嵌入一个近似Frank-Wolfe算法,为上层模型设计了一个合理算法。上下层的联合求解是通过在求解上层模型时,调用下层模型求解算法得到给定需求分布条件下路段分配流量来实现的。数值算例分析验证了新模型与算法的有效性。研究结果不仅拓展了现有OD量反推研究理论的应用场景,也为相关建模分析求解提供了新的思路方法。

To deal with the situation with given traffic demand generated from origins and partial observed link flows,a bi-level programming model of estimation of the OD demand is proposed.The upper level was designed to minimize the difference between the assigned link flows and the observed link flows.To properly describe the route choosing behaviors of travelers,the user equilibrium traffic assignment model was adopted in the lower level model.A proper algorithm was designed for the upper level model by embedding an approximate Frank-Wolfe algorithm into the augmented Lagrange multiplier algorithm.To obtain the joint solution of the bi-level model,the algorithm of lower level model with given OD demands should be called repeatedly to obtain the assigned link flow.The numerical example verified the effectiveness and efficiency of the new model and algorithm.The research result not only extends the application setting of the existing theory of estimation of OD demands,but also provides new ideas and methods to formulate and analyze the related problems.