Hyperpaths in Network Based on Transit Schedules

Abstract

with a link-to-link connector that captures both the feasibility and the cost of making a connection between the scheduled links. In this way, separate links for boarding and alighting behavior are not necessary (as might be needed in a node-based representation). Instead, the hyperlink includes the cost for each transfer between two consecutive links and can have a separate cost for each transfer movement, which differs from when a hyperlink cost is on the existing hyperpath.A transit schedule network represented in a link-based scheme gives the same result as node-based models. Each scheduled vehicle trip between two consecutive stops is represented as a single transit schedule link, with a route and a mode. This is called a link-based time-expanded (LBTE) network. Because a basic search unit is along a link and in the link-to-link connections, it is not necessary to expand a physical stop to multiple stops, representing the same stop at different points in time [a diachronic graph (8)]. Thus for network representation, the benefit of the LBTE is twofold: passenger boarding and alighting behavior is represented on a hyperlink, instead of through separate boarding and alighting hyperlinks, and the network size is much smaller than a node-based time-expanded transit schedule network.Because of its efficiency in network representation and its flexibility in representing transit passenger behavior, a logit-based hyperpath choice model is proposed for use on an LBTE transit schedule network. It is assumed that passengers have a preferred arrival time (PAT) at the destination, and thus a backward hyperpath search model is introduced. Because of different perceptions of the generalized cost of travel for each passenger, each hyperlink is managed by a logit-type function for the choice set of schedule alternatives. The proposed hyperpath search model is expected to give more strategic alternatives for passengers on the transit schedule network.This study defines the link-based hyperlink, its cost, and the resulting hyperpath structure. An LBTE transit schedule network compatible with this definition is proposed, along with a weighting function for both deterministic and stochastic assignment cases. A label-correcting algorithm is provided to solve for the bounded optimal assignment. These algorithms were applied to a transit test network. REPRESENTATION OF NETWORK FOR LINK-BASED HYPERPATH DefinitionsGallo et al. define a hyperlink by using e = [t(e), h(e)], where t(e) is the tail node subset of hyperlink e and h(e) is the head node subset of hyperlink e (15). Each hyperlink is represented in the form (node-link-node). Instead, this paper introduces a (link-to-link) Hyperpaths in Network Based on Transit SchedulesHyunsoo Noh, Mark Hickman, and Alireza Khani The use of hyperpaths in public transportation was conceptualized by Nguyen et al. (1), Nguyen and Pallottino (2), and Spiess and Florian (3). Extensions have since been studied, including k-shortest hyperpaths (4, 5) and the one-to-one hyperpath (6). For a transit ...

Modeling Transit and Intermodal Tours in a Dynamic Multimodal Network

“…The model has undergone several improvements by the authors as a result of its application in the past 3 years. Among such improvements and considered as future work are applying a logit route choice model for improved behavioral modeling (18)(19)(20)(21), incorporating capacity constraints in the transit assignment model (18,20,21), and modeling transit system reliability. In addition, validation of the results is an essential future work before the model is used for decision making or scenario analyses.…”

Algorithm for Intermodal Optimal Multidestination Tour with Dynamic Travel Times

“…In the TBSP, unlike most studies of schedule-based transit systems (17,18), the network structure is not a time-expanded network. It is actually a trip-based schedule network, which means that a set of routes exists for each stop, a set of trips exists for each route, and a set of stops and the schedule times exists for each trip.…”

Integrated Frequency Allocation and User Assignment in Multimodal Transit Networks

“…To assign travelers onto optimal paths, a hyperpath algorithm is developed (24). For a better understanding of hyperpaths see Verbas and Mahmassani (24), Nguyen and Pallottino (25,26), Spiess and Florian (27), and Noh et al (28).…”