T3e Webinar Overview

Signal Timing Optimization for Improved Mobility and Air Quality

The U.S. Department of Transportation (U.S. DOT) Intelligent Transportation Systems (ITS) Joint Program Office (JPO) Professional Capacity Building (PCB) Program invites you to an upcoming Talking Technology and Transportation Webinar.

Date: Wednesday, April 10, 2019
Time: 2:00 PM – 3:00 PM ET
Cost: All T3e webinars are free of charge.
PDH: 1.0 View PDH Policy

This event took place on April 10. The archive will be available in May.

T3e Webinars are brought to you by the Intelligent Transportation Systems (ITS) Professional Capacity Building (PCB) Program of the U.S. Department of Transportation’s (U.S. DOT) ITS Joint Program Office (JPO). The purpose of this webinar series is to provide a platform for students to share their research findings and for academic institutions to inform the ITS community of their relevant programs and research. References in this webinar to any specific commercial products, processes, or services, or the use of any trade, firm, or corporation name is for the information and convenience of the public, and does not constitute endorsement, recommendation, or favoring by the U.S. DOT.


In this presentation, attendees will learn about research on a bi-objective signal control system that minimizes a weighted combination of total vehicle (or person) delay and emissions for both cars and buses at signalized intersections. There is a critical need to mitigate congestion and its associated impacts on urban multimodal transportation systems. Simulation tests for a variety of car demands, bus arrivals, and pollutants are performed to test the signal control system. Pareto optimal solutions and the trade-offs between delay and emissions as well as their impact on bus operations for different combinations of the two objectives are presented. The results reveal that the two objectives (delays and emissions) can be conflicting depending on the pollutant type considered and emission rates used for cars and buses. Implementation of the proposed signal timing optimization can be used to assist decision-makers with choosing the appropriate objective weights that maximize their priorities.

Learning Objectives

Following the webinar, the audience will be more knowledgeable on how to:

  • Estimate emissions from cars and buses using macroscopic traffic stream characteristics.
  • Estimate vehicle and person delay for cars and buses traveling in mixed-use lanes.
  • Optimize signal timings to minimize a weighted combination of delay and emissions.
  • Examine trade-offs between pollutant emissions and mobility metrics.

Target Audience

The target audience includes educators, researchers, transportation professionals, and policy makers interested in multi-objective optimization of traffic signal control in urban areas.


Eleni Christofa, Ph.D., Assistant Professor of Civil and Environmental Engineering, University of Massachusetts, Amherst, MA
Eleni Christofa Dr. Christofa’s expertise is in traffic operations and signal control, public transportation, and safety for non-motorized users. Dr. Christofa’s research has focused on the development of sustainable management strategies and geometric designs that improve person mobility, air quality, and safety in urban multimodal transportation systems. Her research has been funded by the U.S. Department of Energy Advanced Research Projects Agency-Energy (ARPA-E) program, U.S. Department of Transportation through the University Transportation Center program as well as the Massachusetts Departments of Transportation and Public Health. She is a member and paper review coordinator of the Transportaion Research Board (TRB) AHB25 Traffic Signal Systems Committee. She has published more than 20 papers in scientific journals and more than 40 papers in conference proceedings. In 2017 she was named the Transportation Research Board Outstanding Young Member for her contributions to TRB and accomplishments in the transportation profession. Dr. Christofa received her Ph.D. and Masters in Civil and Environmental Engineering from the University of California, Berkeley. She also holds a Diploma in Civil Engineering from the National Technical University of Athens, Greece.


Farnoush Khalighi, Ph.D., Transportation Modeler, Aimsun Inc., New York
Farnoush Khalighi Dr. Khalighi’s research interests include traffic flow theory, public transportation, intelligent transportation systems, and emission impacts of transportation. Her Ph.D. dissertation focused on the development of a bi-objective signal control system to minimize a weighted combination of delays and emissions for cars and buses. She also developed a Cellular Automata simulation tool to assess delay and emissions at roundabouts versus signalized intersections. Dr. Khalighi was recognized with the Women’s Transportation Seminar (WTS)-Boston Claire Barrett Memorial Scholarship in 2015. She received her M.S. and Ph.D. in Transportation Engineering from the University of Massachusetts, Amherst, and her B.S. in Civil Engineering from Sharif University of Technology, Tehran, Iran.


Get technical support

Technical Assistance is available to Federal, State and local transportation agencies through:

ITS Peer Program - The ITS Peer-to-Peer Program puts you in touch with technical experts or experienced peers.
ITS Help Line - The ITS Help Line provides technical support by email or telephone at 866-367-7487.


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