Understanding Seasonal Variation in Individual's Activity Participation and Trip Generation by Using Four Consecutive Two-Week Travel Diary

•Clear trade-offs between mandatory activities and non-mandatory activities, regardless of any seasons.•A positive mutual endogeneity relationship between number of trips and activity duration within the same activity type.•Spring season has larger effects than any season, especially on leisure activity-travel indicators.•Summer season has larger effects than any season on travel time spent for leisure activity by public transport and slow modes.