Hot Stops Study in Houston, Texas (July-August 2023)

Data were the focus of a report by Houston Public Media and a subsequent peer-reviewed journal article in Transportation Research Part D: Transport and Environment. The purpose of this study was to determine how trees and different shelter designs impact heat stress at bus stops. Over 13 days in July–August 2023 in the humid subtropical climate of Houston, Texas, researchers used two sensors (QUESTemp°15, Extech HT200) to objectively measure wet bulb globe temperature (i.e., heat index of air temperature, relative humidity, wind speed, radiation) in the shade from tree canopy and four different shelter designs to compare with unshaded areas at 17 bus stops. Results from multilevel random effects modeling revealed that tree-shaded areas were associated with 3.2°C (5.8°F) lower wet bulb globe temperature compared to unshaded areas (p<0.001). Shelters provided less cooling benefits than trees, and enclosed shelters were less effective than those with open designs. Further, heat stress was more than 3°C (5.4°F) higher under unshaded, enclosed shelters than unshaded areas outside of shelters (p<0.001). Findings reveal that tree planting at transit stops may be a top option to mitigate heat stress, and shelters, if improperly designed, may be a form of maladaptation, amplifying health risk.