NSF Collaborative Research: RAPID: Maintain Mobility and Reduce Infection Through a Resilient Transit and Micromobility System

John MacArthur, Portland State University


The COVID-19 pandemic has caused unprecedented disruptions to health, the economy, and transportation systems in cities. The key strategy to combat growth in the infection rate is through "social distancing," maintaining physical separation from others. This strategy is incompatible with transit systems and ridership in nearly every transit market has plunged, causing agencies to reduce service levels to protect riders and employees. Still, mobility is required in many cities and the ability of cities to rapidly recover from widespread economic shutdown will require improving mobility systems in urban areas. In the past decade, more diverse shared mobility systems have proliferated, potentially improving the resilience and redundancy of the urban transportation system. Most recently, micromobility systems (i.e., bike share and scooter share) have entered cities and supplemented transportation systems in those areas. As a shared personal mobility vehicle, micromobility vehicles have been highly utilized in some markets in the early weeks of the pandemic even as transit ridership has declined. This is an important opportunity to understand how shared micromobility systems complement transit and can support social distancing to limit spread of disease while also facilitating urban transportation recovery. To that end, this study has two main aims. First, the research team will conduct a series of panel surveys for the duration of the pandemic of transit and micromobility users in two medium-sized transportation markets (Nashville and Portland) that have robust micromobility markets. These surveys will query and model mode choice behavior in relation to social distancing requirements, transit captivity, job status, income, activity restrictions, and others. The research team seeks to understand if riders self-regulate transit use and exposure and balance their behavior with perceived risks. The team will use detailed agency and micromobility operator data to track changes in ridership during recovery. The second aim is to project those findings on more aggregate ridership data of transit and micromobility across cities of different sizes and with different COVID-19 infection rates. This will provide detailed understanding of how riders react to pandemic in regard to two main shared modes; transit and micromobility systems.

To date there has been little work on the response of transit to disease outbreaks. The 2002/2003 SARS outbreak provides some aggregate evidence of long-duration drops in transit ridership. This work will provide important insight into disaggregate rider behavior, disease transmission, and personal- and community-risk tolerance. Moreover, this work will explore how emergent modes, like shared micromobility provide opportunities to maintain mobility while reducing close personal contact. Models developed can help predict how city transit systems will recover after a public health crisis. Public health emergencies will continue into the future and preparation on how to react to such emergencies will be important. For example, micromobility systems may provide much needed transportation services to supplement limited transit service. Understanding the dual roles of micromobility and transit will assist in limiting disease transmission and recovering the transportation system. Policy responses could be based on evidence generated in this study for the current and future infectious disease pandemics.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Project Details

Project Type:
Project Status:
In Progress
End Date:
March 31,2021
UTC Grant Cycle:
non-UTC project
UTC Funding: