Avoiding Bunching with Bus-Following Models and Bus-to-Bus Cooperation

Ampountolas, K. and Kring, M. (2015) Avoiding Bunching with Bus-Following Models and Bus-to-Bus Cooperation. In: 94th Annual Meeting of the Transportation Research Board, Washington, DC, 11-15 Jan 2015,

Abstract

This paper concerns the modelling and control of the bus bunching problem. Bunching is an in- stability problem where buses operating on high frequency public transport lines arrive at stops in bunches. Bunching reduces the reliability of bus services and forces passengers face increased waiting times at bus stops. In this work, we unveil that bus-following models can be used to de- sign bus-to-bus collaborative control strategies and mitigate bunching. The use of bus-following models avoids the explicit modelling of bus-stops which would render the resulting problem dis- crete, with events occurring at arbitrary time intervals. In a “follow-the-leader" two-bus system, bus-to-bus communication allows the driver of the following bus to observe the position and speed of his own bus and (from a remote distance) that of a lead bus operating in the same transport line. The information transmitted from the lead bus is used to control the speed of the follower in order to eliminate bunching. In this framework, we first propose practical linear and nonlinear control laws to regulate space headways and speeds, which would lead to bunching cure. Then a rigorous combined state estimation and remote control scheme, which is based on the Linear- Quadratic Gaussian (LQG) control theory is developed to capture the effect of bus stops, traffic disturbances, and randomness in passenger arrivals. To investigate the behaviour and performance of the developed approaches to the problem of bus bunching two different lines are used, includ- ing the 9-kilometre 1-California line in San Francisco with about 50 arbitrary spaced bus stops. Simulations with real passenger data obtained from the San Francisco Municipal Transportation Agency (SFMTA) are carried out. Results show bunching avoidance and significant improvements in terms of schedule reliability of bus services and delays. The proposed control laws are robust, scalable in terms of public transport network size, and thus easy to implement in real-life settings.

• Item Type: Conference Proceedings
• Additional Information: Paper # 15-1770
• Keywords: Bus bunching, bus-following models, bus-to-bus cooperation, bus schedule reliabil- ity, Linear-Quadratic Gaussian (LQG) control
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Ampountolas, Dr Konstantinos
• Authors: Ampountolas, K., and Kring, M.
• College/School: College of Science and Engineering > School of Engineering > Infrastructure and Environment

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