PUCE: Protecting vulnerable road Users exposed to Contagion sprEad in public transit systems during and aftermath of a pandemic

Research Project, 2021 – 2022

Pandemic is arguably the biggest global risk for humankind. The world is apparently not well prepared for an epidemic outbreak (e.g. the COVID-19 pandemic). The key to prepare for an outbreak is about early tracing and containment, and if unsuccessful, about mitigation and damage control. Road users that are exposed to contagion spread through transport networks are deemed as “vulnerable users” in this research. In order to protect these “vulnerable users” that are in close physical proximities with a confirmed case (even worse if without symptom) in a transport network, we establish an interdisciplinary team including transport modelers, epidemiologists, chief physicians of the center for disease control and prevention, as well as big data scientists, to collectively develop models to identify “familiar strangers” for early contact tracing and containment. Indeed, although it is straightforward to trace family members and neighbors (home proximity) and co-workers (workplace proximity), it is very difficult to identify the potential spread and infection in transport network from home to workplace (transit proximity).

In this research, we will first identify the passengers’ physical contact network via high-resolution mobility data (in collaboration with Vasttrafik and Upplands Lokaltrafik). Then we will develop a novel framework of contagion spread in large-scale urban environments. Based upon it, we are able to develop an agent-based contagion transmission simulation for early detection, tracing and containment of epidemic outbreaks. In our model, we plan to take into account the unique features of infectious disease: transmissibility of virus (R0), incubation period, ability of self-immunity, individual-based recovery rate, and contact duration in the network. We will work together with transit operators to re-design our public transit systems (route design and timetabling) to dissolve the “hotspots” of “packed people” in buses, trams and stations. The subsequent waves of a pandemic might be even deadlier (e.g. 1917 flu) due to the retaliatory growth of urban mobility, people’s recklessness aftermath the first wave, and/or viral mutations increasing the virulence. With our re-designed public transit system, the damage can be largely controlled if the second and third waves of COVID-19 actually come. This collective effort will contribute to the robustness of our urban society.