How Extreme Weather Affects Public Transportation in US Cities

Due to climate change, the weather patterns in the United States are undergoing significant changes. There is an increase in severe heatwaves and heavy rainfall, while the frequency of cold weather events is decreasing.

Extreme weather events disproportionately affect lower-income households, particularly regarding their access to public transportation, which many rely on for daily mobility and essential activities.

Researchers at the University of Oregon released a study in December 2024 titled “The impacts of extreme weather events on U.S. Public transit ridership”. The study explores the influence of climate change on public transportation usage.

By examining data from 48 U.S. cities between 2002 and 2019, the researchers analysed how public transit ridership relates to extreme weather events, including very hot or cold days and days with heavy rain or snow. This research aimed to understand how this relationship has changed over nearly two decades and whether it differs according to factors such as income and demographic characteristics.

According to the authors, previous studies showed how the weather can influence people’s travel behaviour. Some research has focused on detailed data, such as bus-stop ridership and smart card use, to examine how weather affects access to transportation.

Nevertheless, there are still knowledge gaps on how extreme weather affects public transit use across different areas and social groups. Additionally, the growth of shared mobility services such as ride-hailing, bike sharing, and e-scooters in the last decade may change this trend as people gain more travel options.

The research has three main objectives.

• First, to assess the average impact of extreme weather on unlinked passenger trips (UPT) per capita—a passenger trip taken on a single vehicle like a bus or subway train, serving as a proxy for public transit usage.
• Second, to analyse whether this relationship has undergone significant changes over almost twenty years.
• Thirdly, to explore variations in impact based on socio-economic factors, including income levels and the unique characteristics of different populations.

The study uses ordinary least squares (OLS) regression analyses to show that public transit ridership decreases slightly but significantly during extreme weather events. It finds that bus ridership is more affected than rail services in these situations. Specifically, the number of transit trips tends to drop on days with extreme heat or cold and during heavy rainfall.

Interestingly, the most substantial drops in ridership on intensely hot days were observed later in the study period, particularly in lower-income cities. Furthermore, the results indicate that bus ridership experienced more significant fluctuations during prolonged extreme cold or heat episodes, whereas rail ridership remained relatively stable despite these challenging weather conditions.

Nicole Ngo, the study’s primary author and associate professor with the UO’s School of Planning Public Policy and Management, says, “A growing number of studies demonstrate the impact of climate change on travel behaviour”. Adding, “But those tend to focus on one city over a narrow period. It’s useful to quantify these trends and confirm they apply nationwide. This will have ramifications for transit agencies down the line” (Dorsch, 2025).

Ngo emphasises that people’s travel behaviour and choices related to public transport and commuting affect weekends more than weekdays. For example, on an extremely hot day, individuals may still take a bus or train to work, but on weekends, they might cancel plans, such as visiting a friend, if it requires walking to a bus stop in the oppressive heat. Instead of taking public transport, they might opt for ride-hailing services like Uber or Lyft, even if it costs more.

She hopes the study’s findings will assist city planners and transportation officials in addressing climate change challenges.