BOGOTÁ, COLOMBIA, May 9, 2024

A new study examining transportation policies in Bogotá, Colombia reveals important trade-offs between equitable access to public transportation and physical activity levels. Researchers found that fare subsidies boosted public transportation use, particularly among low-income residents. These subsidies, however, also decreased walking trips, reducing urban residents’ attainment of World Health Organization physical activity recommendations.

This research, "Uncovering physical activity tradeoffs in transportation policy: A spatial agent-based model of Bogotá, Colombia," was led by members of the Urban Health in Latin America (SALURBAL) Project, which is funded by the Wellcome Trust, and published in the International Journal of Behavioral Nutrition and Physical Activity. Findings highlight the complex relationship between transportation policies, social equity, and individual health and emphasize the need for policymakers to consider these nuances when designing urban policies and interventions.

Public transportation plays a critical role in shaping people’s daily lives and affects our health in many ways. Transport options help determine people’s access to economic and educational opportunities and to healthcare. In rapidly growing cities of low-and-middle-income countries, public transportation is out of reach for many low-income residents. Where the cost of public transport accounts for as much as a quarter of a household’s expenditure, walking becomes a necessity, not a choice. In turn, long walking times can severely limit people’s free time to engage in leisure and health-promoting activities – such as exercising for fun or preparing healthy meals at home.

Public transportation has emerged as a policy priority in Latin America because of these implications for both physical activity and the promotion of health and social equity in cities. However, decision-makers face complex challenges in prioritizing transportation investments, particularly when the relative benefits of these are uncertain and financial and political costs are significant.

To help overcome these challenges, SALURBAL researchers used a wide range of data sources, including information from the Bogotá Household Travel Survey to design a model that simulates the travel behavior of workday commuters living in Bogotá, Colombia. The study applied a novel modelling approach to consider a range of factors that impact people’s decisions about their daily travel, including cost and duration, social norms, and personal safety concerns.

The researchers used this model to simulate the possible impacts of different types of transportation policies. One simulation explored the impact of public transportation fare subsidies, such as free bus services. Another simulation tested to what extent congestion taxes could disincentivize car use in the city. Importantly, the model considered how these policies could impact overall travel time and physical activity, both across the city as a whole and specifically for people in different income groups.

Overall, congestion taxes were found to disincentivize car use and encourage public transportation, without increasing a commuter’s travel times. This decrease was observed among middle- and high-income groups with high rates of car ownership. Fare subsidies, on the other hand, promoted the use of public transportation and reduced travel times while also reducing physical activity levels, particularly among low-income commuters who typically rely on walking as their primary mode of travel.

"Making public transportation affordable is a game-changer for low-income residents," says lead researcher Ivana Stankov, PhD, from the University of South Australia and a member of the SALURBAL group. “These are people who often have no choice but to walk long distances, eating up huge chunks of their day. Affordable public transit gives them a new option – one that can drastically cut down travel times and free up precious hours they can spend with family or engaging in leisure activities.”

Dr. Stankov cautions that while the decline in physical activity among low-income commuters might seem undesirable, “promoting walking as a form of physical activity in circumstances beyond individual choice is problematic because it exploits existing inequities rather than truly empowering people to make healthy choices.”

The study sheds light on how congestion taxes and fare subsidies can be powerful tools for policymakers in low- and middle-income cities, where walking is the primary means of transportation for many residents. While promoting active travel is critical, preventing these policies from exacerbating existing inequalities is equally important. The study's innovative modeling tool empowers policymakers to explore various strategies, evaluate their social and health impacts and trade-offs, and ultimately design policies that benefit all residents.

Full citation: Stankov, I, Meisel, JD, Sarmiento, OL, Delclòs-Alió, Guzman, LA, Hidalgo, D, Hammond, RA & Diez Roux, AV. ‘Uncovering physical activity tradeoffs in transportation policy: A spatial agent-based model of Bogotá, Colombia’, International Journal of Behavioral Nutrition and Physical Activity, DOI: 10.1186/s12966-024-01570-1

The Urban Health in Latin America (SALURBAL) Project studies how urban policies and the environment affect the health of residents of Latin American cities. The results of this project serve as a reference to inform future policies and interventions to make cities healthier, more equitable and sustainable throughout the world. SALURBAL is funded by the Wellcome Trust. To learn more, visit SALURBAL and the SALURBAL Portal.

Contact: Katy Indvik