96 research outputs found
Book of abstracts of the 24th Euro Working Group on Transportation Meeting
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Enhancing network equilibrium models for capturing emerging shared-use mobility services
Driven by the development of vehicle connectivity and automation, shared-use mobility services are expected to play a major role in meeting urban mobility needs. However, existing network equilibrium models cannot adequately model these emerging services, as these models are trip centric, assigning vehicular trips to transportation networks. With shared-use mobility, vehicular trips are the outcome of the interactions between service operators and travelers, a missing ingredient in the current network equilibrium analysis methodology. In this study, we will enhance the methodology by explicitly modeling the behaviors of both service operators and travelers. We will consider two implementations of shared-use mobility: one of a decentralized system in which vehicles choose which areas to serve based on their individually defined utility functions, and one of a centralized system in which a shared-use mobility service provider optimally assigns vehicles to requests based on a system-level objective function. The proposed models are expected to enhance the planning practice for shared-use mobility services.http://deepblue.lib.umich.edu/bitstream/2027.42/162823/5/Enhancing Network Assignment Equilibrium Models for Capturing Emerging Shared-Use Mobility Services.pd
Determining service provider and transport system related effects of ridesourcing services by simulation within the travel demand model mobiTopp
Purpose
Ridesourcing services have become popular recently and play a crucial role in Mobility as a Service (MaaS) offers. With their increasing importance, the need arises to integrate them into travel demand models to investigate transport system-related effects. As strong interdependencies between different people’s choices exist, microscopic and agent-based model approaches are especially suitable for their simulation.
Method
This paper presents the integration of shared and non-shared ridesourcing services (i.e., ride-hailing and ride-pooling) into the agent-based travel demand model mobiTopp. We include a simple vehicle allocation and fleet control component and extend the mode choice by the ridesourcing service. Thus, ridesourcing is integrated into the decision-making processes on an agent’s level, based on the system’s specific current performance, considering current waiting times and detours, among other data.
Results and Discussion
In this paper, we analyze the results concerning provider-related figures such as the number of bookings, trip times, and occupation rates, as well as effects on other travel modes. We performed simulation runs in an exemplary scenario with several variations with up to 1600 vehicles for the city of Stuttgart, Germany. This extension for mobiTopp provides insights into interdependencies between ridesourcing services and other travel modes and may help design and regulate ridesourcing services
Planning of integrated mobility-on-demand and urban transit networks
We envision a multimodal transportation system where Mobility-on-Demand (MoD)
service is used to serve the first mile and last mile of transit trips. For
this purpose, the current research formulates an optimization model for
designing an integrated MoD and urban transit system. The proposed model is a
mixed-integer non-linear programming model that captures the strategic behavior
of passengers in a multimodal network through a passenger assignment model. It
determines which transit routes to operate, the frequency of the operating
routes, the fleet size of vehicles required in each transportation analysis
zone to serve the demand, and the passenger flow on both road and transit
networks. A Benders decomposition approach with several enhancements is
proposed to solve the given optimization program. Computational experiments are
presented for the Sioux Falls multimodal network. The results show a
significant improvement in the congestion in the city center with the
introduction and optimization of an integrated transportation system. The
proposed design allocates more vehicles to the outskirt zones in the network
(to serve the first mile and last mile of transit trips) and more frequency to
the transit routes in the city center. The integrated system significantly
improves the share of transit passengers and their level of service in
comparison to the base optimized transit system. The sensitivity analysis of
the bus and vehicle fleet shows that increasing the number of buses has more
impact on improving the level of service of passengers compared to increasing
the number of MoD vehicles. Finally, we provide managerial insights for
deploying such multimodal service.Comment: 39 pages, 6 figure
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