The Meteorological Modulators: Quantifying Weather’s Influence on Activity-Travel Behavior

This study analyzes the effects of weather conditions on travel demand by developing an integrated database that combines travel data with monthly, daily, and hourly weather information. The travel data were extracted from the 2018–19 CMAP Household Travel Survey, while weather information was obtained from the US Local Climatological Data provided by the National Centers for Environmental Information of the National Oceanic and Atmospheric Administration. The Chicago O’Hare International Airport weather station was used as the sole reference station, reflecting the study’s focus on temporal rather than spatial variability. This study examines the effects of a comprehensive set of weather metrics on activity-travel patterns, focusing on activity participation and mode choice behavior. Descriptive analyses of daily and hourly weather conditions and travel demand reveal how activity-travel behavior changes under varying weather conditions. The empirical analysis applies a mixed logit modeling framework to exclusively capture the impacts of hourly weather conditions and their interactions with demographic and built environment characteristics. An elasticity analysis is employed to assess the magnitude of weather-related effects. The results show that temperature, relative humidity, windspeed, and visibility strongly influence activity-travel behavior, particularly discretionary activity participation and active mode choices. In contrast, mandatory activity participation and single-occupancy vehicle choices are found to be less sensitive to weather variations. Overall, the findings highlight weather as a critical determinant of travel behavior, underscoring the need for dynamic travel demand models using high-resolution weather data and targeted transportation policies and infrastructure that support resilient transportation systems.