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  • Integrating Bus Service Planning with Analysis, Operational Control, and Performance Monitoring

    High quality transit service requires two feedback loops. The first loop, which works in real time, is operational control – taking measures to restore service to schedule. The second loop, which works off-line over a longer time frame, is service planning – making a schedule that reflects realistic operating conditions, is achievable, and allows for and expects interventions for operational control.

    At the heart of both quality loops is a performance monitoring system based on an on-board computer with location tracking capability. It communicates in real time its location and deviation from schedule; for service planning, it records its trajectory during the day and uploads it at night into a database used for service planning.

    This paper shows how service planning can be integrated with operational control using simple illustrations based on the systems that are in place in Eindhoven, the Netherlands. The operational control systems used there are holding at timepoints, and conditional priority at signalized intersections. Late buses request, and are given, priority, while early buses experience normal intersection delay, thus restoring service to its schedule. The analysis and planning system used is TRITAPT (TRIp Time Analysis in Public Transport), a program developed at the Delft University of Technology.

    Delft University of Technology - Traffic and Transportation Research Laboratory

    Northeastern University - Department of Civil and Environmental Engineering

    Presented at the 10th ITS Annual Conference and Exposition, May 1-4, 2000 Boston, MA

  • The Importance of Gain in Driver Assisted Lateral Control

    Using a lateral driver assist system for snowplow operators as an example, the impact on driver performance of subtle changes in control laws was explored. The display for the driver assist system provided integrated information on current lateral position, road orientation and curvature, and a prediction of future location. Changes in driver performance were seen by modifying the gains for terms within the prediction control law. Most notably, removal of the prediction feature or road orientation led to substantially decreased performance. Gain increases above one in the road orientation term led to improved speed, lateral positioning, and steering wheel standard deviation due to the stability improvement of the driver assist system.

    University of California, Berkeley - California Partners for Advanced Transit and Highways (PATH)

    Presented at the 10th ITS Annual Conference and Exposition, May 1-4, 2000 Boston, MA

  • Implementation Challenges of the Gateway Traveler Information System

    As one of the four priority corridors originally established by the US Congress under the ISTEA legislation, the Gary-Chicago-Milwaukee (GCM) Corridor has been the scene of numerous, ITS projects. One of the largest and most complex is the Gateway Traveler Information System (TIS) which is being led by the Illinois Department of Transportation (IDOT). Parsons Transportation Group is assisting IDOT in their work. The Gateway is one of the largest, most complex TIS ever implemented. It involves the collection of transportation related data within a three state area and distribution of this data back to the sources as well as to the public and information service providers. It also includes provision for joint control of field devices across jurisdictional boundaries. In implementing the Gateway, several issues needed to be addressed, many of which have national significance. This paper presents an overview of these issues and details the actions taken to mitigate the effect of these issues. Among the issues discussed are the results of the Corridor’s efforts to exchange geographically based data across several different databases. This is a necessity if information is to be transmitted electronically from computer to computer without any operator intervention. Currently, there are at least eight different location referencing systems in use within the Corridor. The Gateway is not the only system in the US facing this problem, and as a result, a national Location Referencing Messaging System (LRMS) developed by Oak Ridge Laboratory under a contract with the Federal Highway Administration has been implemented in the Corridor. Other issues addressed in this paper include: the need to be NTCIP compliant, specifically what is meant by this; how the design accommodates changes in National Transportation Communication for ITS Protocol (NTCIP); and what is considered as the baseline for NTCIP compliance. Additional issues addressed include: data fusion/verification; consensus building amongst diverse participants and procurement difficulties.

    Illinois Department of Transportation

    Parsons Transportation Group

    Presented at the 10th ITS Annual Conference and Exposition, May 1-4, 2000 Boston, MA

  • Human Driver Model for SmartAHS based on Cognitive and Control Approaches

    The general architecture of the cognitive and control human driver model, which we are incorporating into SmartAHS1, is presented to allow simultaneous simulation of vehicles controlled by drivers and semi-automated systems. Among seven principal modules in the model, perception, tactical, and operational modules are investigated in more detail and are used to describe driving behavior in car following.

    The tactical and operational modules consist of multiple layers, based on a hierarchical structure. They communicate to each other by means of flag, channel, and messages. In particular, a computational driving schema in the tactical module is designed by use of a finite state machine in order to deal with its hybrid structure. Moreover, the schema is chosen through a categorization process. A proposed regional decision map allows transition of states in the schema. Based on the perception module and decision in the tactical module, time gap control and range-rate control are used in the operational module to achieve a local goal for car following task.

    The proposed modules have been implemented in the SmartAHS framework by use of SHIFT simulation language to perform the car following simulation. For the purpose of simulations, the design parameters for car following have been chosen through a literature review. However, they can be adjusted through real field test of a driver. This method permits to obtain realistic micro-level simulation results, and then, to describe an individual driving style.

    University of California at Berkeley - California PATH

    Department of Mechanical Engineering

    Institute of Transportation Studies

    Presented at the 10th ITS Annual Conference and Exposition, May 1-4, 2000 Boston, MA

  • An Evaluation of ITS for Incident Management in Second-Tier Cities: A Fargo, ND Case Study

    Congestion on urban freeways, which adversely affects the economy, environment, and quality of life, continues to be a major problem in the United States. Minor incidents, such as minor traffic accidents, stalled vehicles, and special events, account for the majority of urban freeway congestion. Due to the problems associated with freeway incidents, many large metropolitan areas have implemented Incident Management Systems (IMS) to alleviate congestion and safety problems associated with incidents. These systems provide motorists with timely and accurate information to avoid incident locations. Therefore, motorists will experience reductions in travel time and secondary accidents, while increasing speeds and capacity during an incident. Incident management systems have been implemented mainly in large urban areas; however, little is known about the possible benefits in smaller urban areas (second-tier cities).

    This study examined the feasibility of implementing IMS in small/medium size urban areas using a case study of the I-29 corridor in Fargo, ND. Due to the lack of knowledge and information regarding the possible benefits of implementing an IMS in smaller urban areas, the evaluation was performed using a simulation model to compare base cases to ITS enhanced cases. The INTEGRATION simulation model was used to estimate the potential benefits of an IMS which employs Advanced Traveler Information Systems (ATIS) and Advanced Traffic Management Systems (ATMS). The study simulated a hypothetical one-lane-blocking incident having a duration of 20 minutes.

    The case study analysis revealed that the combination of ATIS and ATMS provided the most favorable network benefits under the 20-minute incident. The IMS reduced incident travel times by 13 percent (city arterials), 28 percent (freeways), and 18 percent (overall network); average trip times were reduced by 20 percent (overall network); and average speeds increased by 21 percent (overall network).

    North Dakota State University - Advanced Traffic Analysis Center - Upper Great Plains Transportation Institute

    Presented at the 10th ITS Annual Conference and Exposition, May 1-4, 2000 Boston, MA

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