Portrait of Zhengtian Xu

Zhengtian Xu awarded HKSTS Outstanding Dissertation Award and TSL Dissertation Prize

Both awards honor excellence in dissertations on the topic of transportation research.

Recent PhD alum Zhengtian Xu has received two awards for his dissertation On the Empty Miles of Ride-Sourcing Services: Theory, Observation and Countermeasures: the 2021Hong Kong Society for Transportation Studies (HKSTS) Outstanding Dissertation Award cum Gordon Newell Memorial Prize and the 2021 Society of the Institute for Operations Research and the Management Sciences (INFORMS) Transportation Science and Logistics (TSL) Dissertation Prize. 

According to the NKSTS website, the society established the Outstanding Dissertation Award “to promote transportation research and education in Asia.” The Gordon Newell Memorial Prize is named for a late faculty member at the University of California at Berkeley “in recognition of his significant contributions to scientific research and education in traffic and transportation theories.”

The TSL Dissertation Prize is the oldest and most prestigious honor for doctoral dissertations in the transportation science and logistics area. The award honors the top dissertation that demonstrates fundamental contributions and originality of the ideas or methods, practical importance or applicability in solving important real problems, and clarity and excellence of the exposition.

The proliferation of smartphones in recent years has catalyzed the rapid growth of ride-sourcing services such as Uber, Lyft, and Didi Chuxing. But to overcome the physical and temporal frictions that separate drivers from customers and effectively reposition themselves towards desired destinations, ride-sourcing services generate a significant number of vacant trips. These empty miles traveled result in inefficient use of the available fleet and increase traffic demand, posing substantial impacts on system operations. 

In his dissertation, Xu investigated the formation and consequences of empty miles in ride-sourcing services and proposed countermeasures to bolster system performance. He was advised by Professor Yafeng Yin.

Xu finished his PhD in Summer 2020 and started as an Assistant Professor at the George Washington (GW) University Department of Civil and Environmental Engineering in Fall 2020. His research focuses on mathematical modeling, optimization, and empirical operations management of urban transportation systems. He leads the Sustainable Urban Mobility Lab (The SUM Lab) at the GW Transportation Program, aiming to understand, promote, and regulate emerging urban mobility services and vehicle technologies.

This article was updated on October 26, 2021 to include the TSL Dissertation Prize.


Portrait of Mason Hinawi
Mason Hinawi

Marketing Communications Specialist
Department of Civil and Environmental Engineering