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Public defence of doctoral thesis 7 October

Published Sep 20, 2022

Welcome to David Leffler's public defence of his doctoral thesis on "Simulation-based Evaluation of Fixed to Flexible Transit"

Time: Fri 2022-10-07 10.00

Location: D37, Lindstedtsvägen 5, Stockholm

Video link: kth-se.zoom.us/j/63780032834

Language: English

Subject area: Transport Science, Transport Systems

Doctoral student: David Leffler , Transportplanering, Centrum för trafikforskning, CTR

Opponent: Associate Professor Chris Tampère, KU Leuven, Belgium

Supervisor: Docent Erik Jenelius, Transportplanering, Centrum för trafikforskning, CTR; PhD Wilco Burghout, Transportplanering, Centrum för trafikforskning, CTR; PhD Oded Cats, Transportplanering, Centrum för trafikforskning, CTR

Abstract:

Preliminary studies have indicated that reallocating resources from fixed transit services with low utilization rates to flexible transit services can improve public transit accessibility in low demand-density areas. Studies have also shown that shared automated vehicle services can drastically reduce the number of vehicles required to serve urban transport demand, reducing congestion and pollution. New technologies and flexible transit designs could foster city infrastructure planning oriented around people instead of cars. However, if high enough levels of ride-pooling and integration with existing high-capacity transit are not achieved, there are also indications that such services can poach passengers from more sustainable modes of transportation, increase total vehicle-kilometers traveled, and amplify trends of urban congestion.

A question that arises is how to evaluate the effects of novel flexible transport solutions as a competing or complementary alternative to traditional fixed public transit under alternative demand settings, technological settings, road network topologies, and objectives. Flexible transit systems are difficult to trial in parallel with the technologies that inspire their design, due to their cost of implementation and the time frame required for stable use patterns to emerge. 

Agent-based simulation frameworks have been utilized to systematically understand and develop theories around the dynamics of transport systems and traveler behavior using diverse data sources, while ideally also forecasting the effect of alternative transit designs and operational policies. Interest in applying agent-based simulation models to evaluate flexible transit systems has grown significantly over the past decade, however, are still limited in their ability to represent the vast flexible transit service design space. In this thesis, flexible public transit systems ranging from services with partially fixed routes and timetables to services with demand-responsive routes and timetables determined in real-time are appraised through extensions to the public transit simulation framework BusMezzo.

Read the full abstract here.

Belongs to: Centre for Traffic Research (CTR)
Last changed: Sep 20, 2022