Health Impacts of City-Wide Zero-Fare Bus Transit: A Natural Experiment

PROJECT ABSTRACT
Wide-reaching efforts are needed to increase population levels of physical activity and healthy eating in low-
income groups for obesity- and type 2 diabetes prevention/control. Low-income groups experience higher rates
of obesity and diabetes than the general population and the COVID-19 pandemic has made these groups even
more vulnerable to developing these preventable chronic diseases. Active transportation is an underused
source of physical activity but is particularly relevant to low-income groups. A major and consistent correlate of
active transportation is use of public transit, and transit users engage in 5-15 more minutes/day of overall PA
that non-users. Public transit may also support access to healthy eating and health services. Citywide policies to
increase use of public transit have promise for improving health markers but have been substantially
underexplored. As an effort to improve economic conditions among low-income groups, Kansas City, MO
(KCMO; 500K residents; 43,000 daily bus trips) has become the only major city in the U.S. to permanently
adopt an ongoing zero-fare bus transit (ZBT) policy. The policy has eliminated all bus fares across the city. This
provides an extraordinary opportunity to examine impacts of such policies on bus ridership and subsequently
on bus users' physical activity, healthy eating, and weight status. In this proposed study, we will collect bus
ridership data before and up to 3 years after ZBT in KCMO and multiple comparison cities. To investigate
health information, study participants will be recruited from a large primary care health system serving low-
income communities. Participants will complete measures of bus use, and height and weight information will be
obtained from the health system's electronic health record before and up to 3 years after ZBT. A subsample of
participants will complete a 7-day objective physical activity assessment and questionnaires on their healthy
eating, perceptions of the ZBT policy, and barriers/facilitators to riding the bus. Community residents will collect
neighborhood environment information around bus stops to test as barriers to bus ridership and support
advocacy efforts. A state-of-the-art synthetic control approach will be used to compare ridership trends across
cities and weight status trajectories between post-ZBT bus users and non-bus users. The synthetic controls will
be a weighted combination of multiple control participants to provide a better comparison than any single
control alone. This study has significant implications for advancing knowledge and evidence on the potential
health impacts of ZBT policies. Findings will produce information that will be usable by other natural
experiment researchers and healthcare entities, as well as by local, state, and federal governments in making
determinations on use of public policy approaches such as ZBT as a lever for obesity- and diabetes-related
risk reduction in low-income communities.

Grant Number: 5R01DK132350-04
NIH Institute/Center: NIH
Principal Investigator: Jannette Berkley-Patton