Optimal design of intersecting bimodal transit networks in a grid city

Abstract

The urban transit system in a real city usually has two major components: a sparse express (e.g. rail) network and a dense local (e.g. bus) network. The two networks intersect and interweave with each other throughout the city to furnish various route options for serving transit patrons with distinct ODs. The optimal design problem of this bimodal transit system, however, has not been well explored in the literature, partly due to the difficulty of modeling the patrons' complex route choice behavior in the bimodal networks. In light of this, we formulate parsimonious continuum models for minimizing the total cost of the patrons and the transit agency for an intersecting bimodal transit network in a grid city, where the perpendicular local and express lines intersect at transfer stops. Seven distinct route types are identified in this network, which represent realistic intra-and inter-modal route options. A lower-level assignment problem between these routes is embedded in the upper-level network design optimization problem. We develop an efficient method to find near-optimal designs of the intersecting network. Numerical results unveil a number of insightful findings, e.g., that sizable cost savings are observed for the intersecting bimodal design as compared to the single-mode designs for moderate to high demand levels, and that only moderate benefits are observed as compared to the trunk-feeder designs under certain operating conditions. We also show that the conventional practice of designing the local and express networks separately would greatly undermine the benefit of the bimodal system.

Analysis of a Flexible Transit Network in a Radial Street Pattern

“…e results veri ed that the radial type outperforms the grid one. Fan et al [43] developed continuum models to investigate the bimodel transit system. In their study, trips are grouped into ve types.…”

A Bi-Level Programming Model for Optimal Bus Stop Spacing of a Bus Rapid Transit System

“…The studies can partly be categorized into a non-deterministic polynomial problem, which refers to the existence of non-deterministic problems that can be solved by a polynomial algorithm and belongs to a non-deterministic polynomial operation problem, and an enumeration and heuristic search algorithm are used in the process of solving the model. To better understand optimum stop spacing and the influence of different stop spacing methods on passenger and bus travel times, as well as the transit system, a multi-objective optimization model is developed to establish the relationship between stop spacing and average passenger travel times [21][22][23]. Stop spacing is an important determinant when planning a transit system since it has an influence on the service level, as well as the operational costs.…”

Comparison of Bus Network Structures in Face of Urban Dispersion for a Ring-Radial City

“…Chen and Nie (2018) present an alternative feeder service to complement a network composed by fixed routes. In Fan et al (2018), the authors propose a model for the design of bimodal transit networks. Li and Wang (2018) make a combined design of cordon tolls for private vehicles and the bus service.…”

“…Finally, this model considers simple transit systems that only work with one network structure. However, if more complex demand representations are assumed, the analysis of hierarchical systems would be interesting (Fan et al 2018;Van Nes 2002). Mixed structures could better satisfy the diverse mobility requirements.…”