One of the biggest challenges in operating on-demand mobility services is the need to dynamically reposition idle vehicles, whether they are taxis, shared vehicles/bikes, or empty shuttles. This latest research with Dr. Hamid R. Sayarshad at Cornell University proposes new models and algorithms to anticipate future demand for the problem by approximating future opportunity costs with queue delay. In addition, we formulated a lower bound of the queueing-based location model from Marianov & Serra that can be solved much more computationally efficiently. Simulation tests in a controlled study area with NYC taxi data suggests the feasibility of nearly 30% improvement over myopic positioning techniques that do not use data to look ahead.
This work was initially undertaken when Hamid was a PhD student with funding support from the Canada Research Chairs program. Resources from C2SMART are also acknowledged.
Gisselle, one of undergraduate summer researchers at BUILT, is the recipient of the Susan Kupferman Memorial Undergraduate Scholarship from WTS. She will receive the award at the WTS Gala at the Battery Park Garden on October 4th. Congrats!
In the latest MIT Technology Review article, “The Startup Behind NYC’s Plan to Replace Phone Booths with 7,500 Connected Kiosks“, Elizabeth Woyke interviews Prof. Chow about the role that public kiosks can play to relay information.
Recently, TLC announced using Via’s software to enable yellow taxi sharing (https://lnkd.in/dxf-MU9) in favor of a taxi sharing policy. Our latest NSF-funded paper with researchers from NYU Tandon, CUSP, and Courant (Ziyi Ma, Matthew Urbanek, Maria Alejandra Pardo Baquero, Xuebo Lai), now in press, quantifies this benefit for riders that use taxi to access the airport (~10% improvement in consumer surplus) and demonstrate how different matching policies can significantly affect the spatial distribution of that benefit.
Ziyi Ma was supported by the NYU Undergraduate Summer Research Program. Joseph Chow was partially supported by National Science Foundation grant CMMI-1634973. The JFK airport taxi mode choice survey was shared by PANYNJ, which is gratefully acknowledged.
The open access paper can be found here: http://www.sciencedirect.com/science/article/pii/S2046043017300217.
The latest paper, a joint effort between Yueshuai Brian He, Prof. Chow, and U. Toronto researcher Dr. Mehdi Nourinejad, has been accepted for presentation in the IEEE Intelligent Transportation Systems Conference held in Yokohama in fall 2017. The paper topic, “A Privacy Design Problem for Sharing Transport Service Tour Data”, investigates a method to protect the privacy of a private transport operator’s tour data by anonymizing it under the constraint of providing sufficiently accurate user performance metrics for public use. This work should be increasingly important as public agencies and private operators like Via and Lyft seek out data sharing arrangements to support smart cities.
This research is supported by NSF CAREER grant CMMI-1652735.
A preprint of the paper can be found here: https://www.researchgate.net/publication/318451988_A_Privacy_Design_Problem_for_Sharing_Transport_Service_Tour_Data
Our work on simulation-based evaluation of Mobility as a Service as a “2-sided market” is now published in TR Part B. The goal in this work is to develop a tool that can compare “apples to oranges” where the MaaS operator’s decisions and policies are also dependent on user interaction–whether at “within day” level or at “day-to-day” level of dependency. For example, this would allow a city agency to compare the welfare effects of a TNC with a particular surge pricing policy (within day dependency) with another scenario where an EV car sharing company may alter fleet size, composition, pricing policies over time (day-to-day).
Dr. Djavadian was supported by the Canada Research Chairs program and an NSERC Discovery Grant. Prof. Chow was partly supported by the C2SMART University Transportation Center. An early version of this work was presented at IATBR 2015 in Windsor, UK.
Congratulations to these two students on passing their qualifying exams today!
Collaborative work with researchers from University of Toronto and Ryerson University will be presented at the first triennial TSL Conference from INFORMS at Loyola University, Chicago on July 26 – 29, 2017. The title of the topic is “Optimal discount policies for transit agencies: the case of pass programs and loyalty programs”.
Diego Correa will be presenting on the topic “Data-driven spatial-temporal dynamic equilibrium matching models of welfare effects from New York City taxi and Uber markets” in a session on Transport Economics and Operation in the Traffic Flow Theory and Control stream at the 21st Triennial conference on “OR/Analytics for a better world” to be held between July 17-21, 2017 in Quebec City, Canada. This work is under joint supervision of Professors Joseph Chow and Kaan Ozbay.
They conduct an empirical study to find the relationship between the built environment, service supply, and user demand by time of day for Uber using a spatial dynamic equilibrium taxi matching model. Given a matching friction, a spatial distribution of demand activities, and service coverage, the model outputs equilibrium fleet sizes, matches, and social welfare by zone and time of day.
The International Federation of Operational Research Societies (IFORS) is an umbrella organization for national operations research societies of over 45 countries from four geographical regions: Asia-Pacific, Europe, North America, and South America. IFORS conferences are triennial memorable events. IFORS 2017 will bring together operational researchers from around the globe.