2013 Session: 279

• Dynamic System Optimal Routing In Multimodal Transit Network
  Abstract: The system optimal routing problem has been widely studied for road network while it is less considered for public transit system. Traditional shortest-path-based multimodal itinerary guidance systems may deteriorate the system performance when the assigned lines become congested. For this issue, we formulate the dynamic system optimal routing model for multimodal transit system. The transit system is represented by a multilevel graph to explicitly simulate passenger flow and transit system operations. A solution algorithm based on the cross entropy method is proposed, and its performance is compared with the method of successive averages in static and dynamic cases. Numerical study on a simple multimodal transit network provides the basis for comparing the system optimal routing and user optimal routing under different congestion levels.
  Authors: Ma, Tai-Yu; Lebacque, Jean-Patrick
  Authors: Ma, Tai-Yu; Lebacque, Jean-Patrick
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Planning and Forecasting; Public Transportation
  Session: 279
  Paper Number: 13-1247
• Energy-Efficient Operation of Subway Systems
  Abstract: To reduce the operation cost and then improve the operational efficiency, people are paying more and moreattention to the energy-efficient operation of subway systems. In this paper, we present and compare to twoalgorithms to optimize the energy-efficient speed profile for trains of subway systems, which can reduce theenergy consumption of train operations. Firstly, we formulate a mixed integer linear programming (MILP)model to get the optimal trajectory for trains. Secondly, we present an integrated algorithm for optimizingthe timetable for the entire route together with the speed profiles between successive stations, which is calledas integrated timetable. Finally, we give some numerical examples to illustrate the validity of the algorithmsbased on the data from the Beijing YiZhuang subway line in China.
  Authors: Su, Shuai
  Authors: Su, Shuai
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Planning and Forecasting; Public Transportation
  Session: 279
  Paper Number: 13-2451
• Multiobjective Optimization Model for Transit Fleet Resource Allocation
  Abstract: State and local transit agencies require government support to preserve their aging transit fleet. With passage of time, transit fleet gets older and requires maintenance cost to keep it operational. To provide services at a desired level, transit agencies require maintaining a minimum fleet size. Two imperative considerations from transit planning viewpoint are (1) remaining life of the total fleet, and (2) cost required to maintain the fleet size. When the former is a quality measure indicating the health of the fleet, the latter is an economic measure requiring minimum expenditure levels. Ideally, the agencies would like to maximize the total remaining life of the fleet and minimize the total cost required to maintain the fleet size. In this paper, the authors propose a multi-objective optimization model (MO) to simultaneously incorporate both objectives when subjected to budget and a number of operational constraints. The MO problem is solved by using classical weight sum approach by employing Branch and Bound Algorithm (BBA) that has proven to be better than other solution methodologies. The MO resulted in pareto optimal solutions with the possible trade-off between the two objectives. The model is applied to a real large scale transit fleet system in the state of Michigan, U.S. The case study results demonstrate, the proposed model is compact, efficient, robust and suitable for long range planning with multiple solutions to choose from a pareto optimal frontier. The correlation between decision variables and objective functions has been investigated in-depth and provides important insights. The proposed model can act as a tool for resource allocation for transit fleet among agencies for state and local agencies.Keywords: transit fleet, multi-objective optimization, branch and bound algorithm, pareto optimal
  Authors: Mishra, Sabyasachee; Sharma, Sushant; Mathew, Tom V.; Khasnabis, Snehamay
  Authors: Mishra, Sabyasachee; Sharma, Sushant; Mathew, Tom V.; Khasnabis, Snehamay
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Planning and Forecasting; Public Transportation
  Session: 279
  Paper Number: 13-2225
  Practice-Ready: Yes
• Large-Scale Transit Schedule Coordination Based on Journey Planner Requests
  Abstract: A two-stage stochastic program that reoptimizes multi-modal transit schedules city-wide is presented. The model works by perturbing or offsetting the schedule such that the expected value of waiting times at all transfer points in the system is minimized. Probabilistic information on transfers is gathered from a prototypical journey planner, a public-facing tool that transit riders query to find optimal paths through a multi-modal network. Aggregating journey plans in this manner provides information on optimal transfers as perceived by the service operator, which are then targeted for improvements. The model is implemented on the large-scale transit network of Washington, D.C., where sampled journey plans representing 9% of the daily transit demand is employed to generate a modified schedule that leads to a reduction in passenger wait times by 26.38%. The results serve to demonstrate how operators can take a user-centric view of their system as a fabric of services, gain insights from user interaction, and gain value from coordinating services while accounting for uncertainty.
  Authors: Nair, Rahul; Coffey, Cathal; Pinelli, Fabio; Calabrese, Francesco
  Authors: Nair, Rahul; Coffey, Cathal; Pinelli, Fabio; Calabrese, Francesco
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Planning and Forecasting; Public Transportation
  Session: 279
  Paper Number: 13-4058
  Practice-Ready: Yes
• Evaluating Effectiveness of Video-Based Driver Risk Management Systems on Transit Safety
  Abstract: In the mid-2000s, public transit agencies began testing a new form of onboard video event recorder technology on buses. These video-based driver risk management systems capture a video clip when triggered by an unusual event, such as hard braking, a sharp turn, or impact with an object. This represented the first time that onboard cameras were intentionally focused on transit operators as a safety strategy.The objective of this study was to determine whether video-based driver risk management systems have enhanced passenger safety by reducing the frequency and severity of collisions and injuries, while also identifying lessons learned from the implementation of such systems. Data collected from National Transit Database reports as well as from DriveCam, Inc., one of the video system manufacturers, was analyzed for trends in safety performance that could be linked to adoption of the systems. Additionally, interviews were conducted with the six U.S. transit agencies and three contract operators using the systems to assess the issues faced in implementing the technology and results thus far. The study shows that video-based driver risk management systems appear to have a positive impact on transit safety achieved through a reduction in collisions and injuries, as well as the risky driving behaviors that contribute to them. The systems provide transit mangers with a wealth of information about their employees’ driving habits that was not previously available. Transit agencies should strongly consider investing in video-based driver risk management systems as one component of an overall safety and training program.
  Authors: Litschi, Michael; Haas, Peter J.
  Authors: Litschi, Michael; Haas, Peter J.
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Planning and Forecasting; Public Transportation
  Session: 279
  Paper Number: 13-4087
  Practice-Ready: Yes
• Dynamic System Optimal Routing In Multimodal Transit Network
  Authors: Lebacque, Jean-Patrick
  Authors: Lebacque, Jean-Patrick
  Year: 2013
  Document Type: Presentation
  Subject: Passenger Transportation; Planning and Forecasting; Public Transportation
  Session: 279
  Paper Number: 13-1247
• Multiobjective Optimization Model for Transit Fleet Resource Allocation
  Authors: Mishra, Sabyasachee
  Authors: Mishra, Sabyasachee
  Year: 2013
  Document Type: Presentation
  Subject: Passenger Transportation; Planning and Forecasting; Public Transportation
  Session: 279
  Paper Number: 13-2225
• Energy-Efficient Operation of Subway Systems
  Authors: Su, Shuai
  Authors: Su, Shuai
  Year: 2013
  Document Type: Presentation
  Subject: Passenger Transportation; Planning and Forecasting; Public Transportation
  Session: 279
  Paper Number: 13-2451
• Multiobjective Optimization Model for Transit Fleet Resource Allocation
  Authors: Sharma, Sushant
  Authors: Sharma, Sushant
  Year: 2013
  Document Type: Presentation
  Subject: Passenger Transportation; Planning and Forecasting; Public Transportation
  Session: 279
  Paper Number: 13-2225
• Large-Scale Transit Schedule Coordination Based on Journey Planner Requests
  Authors: Nair, Rahul
  Authors: Nair, Rahul
  Year: 2013
  Document Type: Presentation
  Subject: Passenger Transportation; Planning and Forecasting; Public Transportation
  Session: 279
  Paper Number: 13-4058