Weather factor impacts on commuting to work by bicycle.

OBJECTIVE Quantify the impact of weather conditions on individual decisions to commute to work by bicycle among a diverse panel of adults who commute ≥2 miles each way. METHOD Working adults (n=163) in a northern U.S. state reported transportation mode for four seven-day periods in 2009-2010 that maximized seasonal weather variations. Personal characteristics, trip to work distances, and commuting mode data were linked to location- and time-specific weather data and daylight hours. Analyses focused on effect of weather conditions on reports of commuting by bicycle. RESULTS Participants were diverse in age, gender and bicycle use, but were relatively well-educated; they traveled to work by bicycle on 34.5% of the logged commuting days. Modeling indicated that the likelihood of bicycle commuting increased in the absence of rain (odds ratio=1.91; 95% confidence interval 1.42, 2.57) and with higher temperatures (1.03; 1.02, 1.04), and decreased with snow (0.90; 0.84, 0.98) and wind (0.95; 0.92, 0.97). Independent effects also were found for bicycle commuting distance, gender, and age, but not for daylight hours. CONCLUSION Precipitation, temperature, wind and snow conditions had significant and substantial independent effects on the odds of travel to work by bicycle among a diverse panel of adult bicycle commuters.