Travel demand is dependent on medium and long-term components such as residential location, work location and car ownership. The choice of residence and work location is also an implicit choice of surrounding in terms of shopping facilities and leisure possibilities, which induce a second type of travel demand, which is often recognised as more impulsive and short-term driven.

However, because of the tight connection with any long-term decision, these decisions can essentially be considered as long-term decisions as well. So, in general it seems more appropriate to model travel demand from a long-term model structure, rather than considering travel demand from a short-term perspective with fixed locations as done in recent Danish models such as PETRA and ALTRANS.