This paper presents a Parallel Block-Coordinate Descent (PBCD) algorithm for solving the user equilibrium traffic assignment problem. Most of the existing algorithms for the user equilibrium-based traffic assignment problem are developed and implemented sequentially. This paper aims to study and investigate the parallel computing approach to utilize the widely available parallel computing resources. The PBCD algorithm is developed based on the state-of-the-art path-based algorithm, i.e., the improved path-based gradient projection algorithm (iGP). The computationally expensive components in the iGP are identified and parallelized. A parallel block-coordinate method is proposed to replace the widely used Gauss-Seidel method for the procedure of path flow adjustment. A new rule is proposed to group OD pairs into different blocks. The numerical examples show that the implemented PBCD algorithm can significantly reduce the computing time.

本文提出了一种并行块坐标下降（PBCD）算法来解决用户均衡的交通分配问题。现有的大多数用于基于用户平衡的交通分配问题的算法都是按顺序开发和实现的。本文旨在研究和研究并行计算方法，以利用广泛可用的并行计算资源。PBCD算法是基于最新的基于路径的算法（即改进的基于路径的梯度投影算法（iGP））开发的。识别并并行化iGP中计算上昂贵的组件。提出了一种并行块坐标法来代替广泛使用的高斯-塞德尔方法进行路径流量调整的过程。提出了一条新规则将OD对分组为不同的块。