2013 Session: 818

• Managing Dynamic Vehicle Allocation for Carsharing Systems: Stochastic Programming Approach
  Abstract: Carsharing offers innovative mobility solutions and has been gaining in popularity around the world as an environmentally sustainable, socially responsible and economically feasible mode of transport. It allows members to gain the benefits of private vehicle use without the costs and responsibilities of ownership and provides individuals access to a fleet of shared-use vehicles in a network of locations on a short term as-needed basis. This paper seeks to develop a stochastic optimization framework to address the dynamic vehicle allocation problem for carsharing systems, in which the service operator needs to manage and determine the optimal vehicle allocation in both time and space in order to maximize profits. A multistage stochastic linear programming model with recourse, which can account for system uncertainties such as carsharing demand variation, is formulated and solved. Numerical results are discussed and computational insights are presented based upon a seven-stage experimental network pilot study.
  Authors: Fan, Wei; Xu, Yongneng
  Authors: Fan, Wei; Xu, Yongneng
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 818
  Paper Number: 13-0324
• Implementation Cost Comparison of Different Types of Electric Vehicle Energy Replenishment Technologies for Public Transit Bus Systems
  Abstract: Several different technologies have been developed in order to improve the usage of electric vehicles. Some of the core technologies are those which regard the replenishment of the energy supply. Essentially different in operation, execution time, and implementation and operation costs, to find a fair comparison between those technologies is not a straightforward task. A model using Petri Nets to calculate the minimum amount of resources required to implement each of the solutions is proposed. The model uses as input the target headway (i.e. the time distance between two consecutive buses) and the components cost, and yields a total system cost to achieve that headway. A case study is presented to illustrate the use of such model.
  Authors: Kemper Filho, Paulo; Suh, In-Soo
  Authors: Kemper Filho, Paulo; Suh, In-Soo
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 818
  Paper Number: 13-3632
• Dynamic Transit Service Through Open Mode Integrated Transportation System
  Abstract: This paper presents an overview of the Open Mode Integrated Transportation System (OMITS), introduces its key components and algorithms in the recent development and implementation, and demonstrates the working mechanism of dynamic transit service. The OMITS has been designed to integrate the availability of multiple transit modes into the ridesharing service to provide riders and drivers flexible, efficient, and reliable transportation services, through dynamic matching and routing algorithms and emerging information communication and data mining and fusion technologies. The OMITS App, which is run on a smart phone (iPhone or Android), has been developed for customers to communicate with the OMITS server, detect roadway traffic conditions, and receive driving directions. The travel time for a road section is predicted considering the traffic factors through the historic and real-time traffic data and public transit schedule. Using the multimodal travel system, the OMITS integrates multimodal transit options including the information of time-dependent arc weights, namely travel time, and switching delays and provides the time-dependent multimodal shortest path using the Dijkstra’s algorithm under the FIFO condition. The OMITS system provides an optimized ridesharing and transit service based on spontaneous transportation demands and service availability. A small scale OMITS prototype has been developed and tested in New York City. An example is presented to demonstrate the dynamic transit service algorithm.
  Authors: Yin, Huiming M.; Wang, Liang; Maurin, Paul
  Authors: Yin, Huiming M.; Wang, Liang; Maurin, Paul
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 818
  Paper Number: 13-4385
• Comparing Optimal Relocation Operations with Simulated Relocation Policies in One-Way Carsharing Systems
  Abstract: One-way carsharing systems allow travelers to pick up a car at one station and return it to a different station, thereby causing vehicle imbalances across the stations. In this paper, realistic ways to mitigate that imbalance by relocating vehicles are discussed. Also presented are a new mathematical model to optimize relocation operations that maximize the profitability of the carsharing service and a simulation model to study different real-time relocation policies. Both methods were applied to networks of stations in Lisbon Portugal. Results show that real-time relocation policies, and these policies when combined with optimization techniques, can produce significant increases in profit. In the case where the carsharing system provides maximum coverage of the city area, imbalances in the network resulted in an operating loss of 1160 €/day when no relocation operations were performed. When relocation policies were applied, however, the simulation results indicate that profits of 854 €/day could be achieved, even with increased costs due to relocations. This improvement was achieved through reductions in the number of vehicles needed to satisfy demand and the number of parking spaces needed at stations. This is a key result that demonstrates the importance of relocation operations for sustainably providing a more comprehensive network of stations in one-way carsharing systems, thus reaching a higher number of users in a city.
  Authors: Jorge, Diana Rita Ramos; Correia, Gonçalo Homem de Almeida; Barnhart, Cynthia
  Authors: Jorge, Diana Rita Ramos; Correia, Gonçalo Homem de Almeida; Barnhart, Cynthia
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 818
  Paper Number: 13-4559
• Managing Dynamic Vehicle Allocation for Carsharing Systems: Stochastic Programming Approach
  Authors: Fan, Wei
  Authors: Fan, Wei
  Year: 2013
  Document Type: Presentation
  Subject: Passenger Transportation; Public Transportation
  Session: 818
  Paper Number: 13-0324
• Implementation Cost Comparison of Different Types of Electric Vehicle Energy Replenishment Technologies for Public Transit Bus Systems
  Authors: Suh, In-Soo
  Authors: Suh, In-Soo
  Year: 2013
  Document Type: Presentation
  Subject: Passenger Transportation; Public Transportation
  Session: 818
  Paper Number: 13-3632
• Dynamic Transit Service Through Open Mode Integrated Transportation System
  Authors: Wang, Liang
  Authors: Wang, Liang
  Year: 2013
  Document Type: Presentation
  Subject: Passenger Transportation; Public Transportation
  Session: 818
  Paper Number: 13-4385
• Comparing Optimal Relocation Operations with Simulated Relocation Policies in One-Way Carsharing Systems
  Authors: Jorge, Diana
  Authors: Jorge, Diana
  Year: 2013
  Document Type: Presentation
  Subject: Passenger Transportation; Public Transportation
  Session: 818
  Paper Number: 13-4559