1,Time, as the hours for leisure increase so does the opportunity for travel. Changes in work days or hours, school calendars will affect how and when people can travel. The overall travel pattern has moved from a two week vacation to 6-8 three or four day mini-vacations per year.
2,Money, the majority of travel requires discretionary income. Discretionary income is money left over after all monetary obligations (food, rent and taxes) have been paid.
3,Mobility, is the access to transportation (car, bus, plane, train or ship) and the hours required to get to their destination.
4,Motivation, is the reason people travel. Motivations may include seeking novelty, education, meet new people, adventure or stress reduction.