| Fall 2005 UMASS
Amherst Operations Research / Management Science Seminar Series |
Date: Friday, October 14, 2005 Time: 11:00 AM Location: Isenberg School of Management, Room 112 |
| Speaker: Professor
Clara Fang Department of Civil, Environmental, and Biomedical Engineering University of Hartford West Hartford, CT |
| Biography: Fang (Clara) Fang received her
Ph.D. in transportation engineering from the Pennsylvania State
University in 2004. Presently, she is an Assistant Professor in the
Department of Civil Engineering at the University of Hartford. She has
been working on real-time traffic signal control and optimization for
diamond interchanges, which has previously been recognized as
outstanding Ph.D. dissertation work obtaining a distinction award from
the Pennsylvania State University and a Fellowship from the
Mid-Atlantic Universities Transportation Center. Dr. Fang was one of
the key members carrying out the NCHRP 3-60 project that led to a
revised Chapter 26 for Interchange Ramp Terminals Operational Analysis
of Highway Capacity Manual. Her research is focused on traffic flow
theory, adaptive signal control & optimization, simulation,
intelligent transportation systems (ITS), work zone safety and highway
design. Dr. Fang has been actively involved in the Transportation
Research Board (TRB)’s Traffic Control Systems Committee, and Capacity
and Quality of Service Committee activities. |
| TITLE: Optimal and Adaptive
Signal Control of Diamond Interchanges |
| Abstract: This research has developed a
methodology and a corresponding implementation algorithm to provide
optimal signal control of diamond interchanges in response to real-time
traffic fluctuations. The problem, solved by a forward dynamic
programming (DP) method, is formulated as to find a phase sequencing
decision with a phase duration that makes a pre-specified performance
measure minimized over a finite horizon that rolls forward. The optimal
signal switches over each 2.5-second interval are found for each
horizon of 10 seconds. The optimization process is based on the
advanced vehicle information obtained from loop detectors set back a
certain distance from the stop-line. Vehicle trajectories from
detections till future arrivals and departures are modeled at the
microscopic level to estimate the traffic flows at the stop-line for
each horizon. The DP algorithm is coded in C++ language and dynamically
linked to AIMSUN, a stochastic micro-simulation package, for
evaluation. The simulation results have exhibited that the DP algorithm
is superior to PASSER III and TRANSYT-7F in handling demand
fluctuations for medium to high flow scenarios when the field demand is
increased from the one used in off-line optimization. The performance
of the three algorithms is almost identical if the simulation demand is
similar to off-line demand situation and dose not vary much. |
| This series is organized by the
UMASS Amherst INFORMS Student Chapter. Support for this series is
provided by the Isenberg School of Management, the Department of
Finance and Operations Management, INFORMS, and the John F. Smith
Memorial Fund. For questions, please contact the INFORMS Student Chapter Representative, Ms. Tina Wakolbinger, wakolbinger@som.umass.edu |