Document Type



Doctor of Philosophy (PhD)


Civil Engineering

First Advisor's Name

Mohammed Hadi

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Albert Gan

Second Advisor's Committee Title

Committee member

Third Advisor's Name

Priyanka Alluri

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Xia Jin

Fourth Advisor's Committee Title

Committee member

Fifth Advisor's Name

Wensong Wu

Fifth Advisor's Committee Title

Committee member

Sixth Advisor's Name

Yan Xiao

Sixth Advisor's Committee Title

Committee member


Non-recurrent Congestion, Traffic Signal Control, Data Analytics, High Resolution Data, Machine Learning, Optimization Method

Date of Defense



Improving arterial network performance has become a major challenge that is significantly influenced by signal timing control. In recent years, transportation agencies have begun focusing on Active Arterial Management Program (AAM) strategies to manage the performance of arterial streets under the flagship of Transportation Systems Management & Operations (TSM&O) initiatives. The activation of special traffic signal plans during non-recurrent events is an essential component of AAM and can provide significant benefits in managing congestion.

Events such as surges in demands or lane blockages can create queue spillbacks, even during off-peak periods resulting in delays and spillbacks to upstream intersections. To address this issue, some transportation agencies have started implementing processes to change the signal timing in real time based on traffic signal engineer/expert observations of incident and traffic conditions at the intersections upstream and downstream of congested locations. This dissertation develops methods to automate and enhance such decisions made at traffic management centers. First, a method is developed to learn from experts’ decisions by utilizing a combination of Recursive Partitioning and Regression Decision Tree (RPART) and Fuzzy Rule-Based System (FRBS) to deal with the vagueness and uncertainty of human decisions. This study demonstrates the effectiveness of this method in selecting plans to reduce congestion during non-recurrent events. However, the method can only recommend the changes in green time to the movement affected by the incident and does not give an optimized solution that considers all movements. Thus, there was a need to extend the method to decide how the reduction of green times should be distributed to other movements at the intersection.

Considering the above, this dissertation further develops a method to derive optimized signal timing plans during non-recurrent congestion that considers the operations of the critical direction impacted by the incident, the overall corridor, as well as the critical intersection movement performance. The prerequisite of optimizing the signal plans is the accurate measurements of traffic flow conditions and turning movement counts. It is also important to calibrate any utilized simulation and optimization models to replicate the field traffic states according to field traffic conditions and local driver behaviors.

This study evaluates the identified special signal-timing plan based on both the optimization and the DT and FRBS approaches. Although the DT and FRBS model outputs are able to reduce the existing queue and improve all other performance measures, the evaluation results show that the special signal timing plan obtained from the optimization method produced better performance compared to the DT and FRBS approaches for all of the evaluated non-recurrent conditions. However, there are opportunities to combine both approaches for the best selection of signal plans.




Previously Published In

Tariq, M. T., Massahi, A., Saha, R., & Hadi, M. (2020). Combining Machine Learning and Fuzzy Rule-Based System in Automating Signal Timing Experts’ Decisions during Non-Recurrent Congestion. Transportation Research Record, 0361198120918248.

Tariq, M. T., Hadi, M., & Saha, R. (2021). Using High-Resolution Controller Data in the Calibration of Traffic Simulation Models. Accepted for the 100th Annual Meeting of the Transportation Research Board, Washington DC, USA.



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