Paula Nguyen’s analysis of streetcar bunching incidents

Speaker at podium
Paula Nguyen presents her MASc thesis

Paula Nguyen presented her MASc thesis, Determining the Factors that Influence the Probability and Time to Streetcar Bunching Incidents, at the UT-ITE Friday Seminar Series on September 22, 2017.


Bunching is a common operational problem in surface transit systems with negative impacts on service quality and users’ perception.

While many studies have focused on understanding the causes of bus bunching and developing strategies to mitigate its negative effects, there has been little research on streetcar bunching. This research aims at understanding the factors that impact the likelihood of streetcar bunching and to investigate the factors that impact the time to the initial bunching incident from terminal.

Focusing on Toronto’s streetcar lines, this study developed a binary logistic regression model and an accelerated failure time (AFT) model to address the first and second goals, respectively.  Data from multiple sources, including the automatic vehicle location (AVL) system, were used to estimate the models.

Headway deviations at terminal and the usage of different vehicles types were two interesting factors found to increase the odds of bunching and accelerate the time to bunching.

group of three
Paula with Dr. Ehab Diab (L) and Prof. Amer Shalaby (R)

Short Bio

Paula Nguyen is an MASc student under the supervision of Professor Amer Shalaby in the Department of Civil Engineering at the University of Toronto. Paula has a strong interest in public and active transportation as well as airport planning.  Her research focuses on understanding the causes of streetcar bunching using statistical models.  She received her BASc in Civil Engineering from the University of Windsor. In her spare time, Paula enjoys swimming, exploring green spaces in Toronto, and going to concerts.

This seminar was presented by the University of Toronto Institute of Transportation Engineers (ITE) Student Chapter.