Description:

Roger Chen 

Professor 

 University of Hawaii at Manoa

Abstract: Recent focus on work and related activities during the pandemic has motivated researchers to revisit our understanding of how workers manage their activities over time. In this study, we consider the completion of daily travel-activity patterns from the perspective of a single-server queuing system with vacations, focusing on discretionary activities. From this perspective, travelers are analogous to service facilities, completing activity arrivals and experiencing varying queue lengths over time, due to limited resources. We applied Larson’s Queue Inference Engine (QIE) to infer discretionary activity queues using a sample of observed one-day travel-activity patterns from Oahu, Hawaii, which includes Honolulu. Through this approach, we investigate the concept of activity stress and loads, and their impact on completing discretionary activities across worker segments in the sample. Choice model estimation results reveal a propensity for individuals to complete more discretionary activities when faced with longer activity queues. The inferred activity queue lengths vary, with travelers with disability status having shorter queues relative to workers with flexible schedules. Full-time students encountered longer delays in their activity services (departure from queues) compared to homemakers. Additionally, the timing of queue profile peaks for discretionary activities differed across worker segments. For students and workers with telework options, queues peaked in the afternoon, while for others, this was in the morning. Retired individuals and workers with fixed schedules had the earliest morning peaks.
 
Bio: Dr. Chen is an Associate Professor in the Department of Civil, Environmental and Construction Engineering (CECE) at the University of Hawaii at Manoa (UHM). His research agenda focuses on understanding and modeling the human dimensions of transportation systems. He has worked on models of route and departure time choice, as well as activity-based models of travel demand. He has also worked on the development, estimation, and application of choice models, which have been integrated within dynamic traffic assignment modeling platforms for predicting responses to congestion pricing and varying weather patterns. Dr. Chen is currently a member of AEP35, the standing committee on Information and Communication Technologies (ICT) and Travel Choices, and AEP30 the Standing Committee on Traveler Behavior and Values. He is also co-chair for AEP30(2) the subcommittee on Route Choice and Spatio-Temporal Processes. He received his Ph.D. from the University of Maryland, College Park, and his B.S. and M.S. degrees from the University of Texas at Austin, all in Civil and Environmental Engineering.