The main reason that motivates that trip. For travel day trips, if there is more than one reason for the trip, and the reasons do no involve different destinations, then only the main reason is chosen.
Georgia Institute of Technology
School of City and Regional Planning
245 4th St
Atlanta, GA 30332
The Built Environment and Public Health Clearinghouse was supported by the Centers for Disease Control & Prevention's Office of the National Prevention Strategy and Healthy Community Design Program and made possible through additional support from the American Public Health Association, the National Network of Public Health Institutes, and the American Planning Association's Planning and Community Health Research Center. Interested in adding to and supporting the Clearinghouse? Contact the Clearinghouse at email@example.com.