Figure 1From: Variability and seasonality of active transportation in USA: evidence from the 2001 NHTSMonthly variation of the four variables for age groups (1: total trip; 2: active trip; 3: percentage of people who took active trip; 4: percentage of active trips amongst trips less than one mile). Note: for X axis, 1 means January, 2 means February, and so on.Back to article page