Abstract
Increasing the mobility of the elderly in society is both a societal aim and an aim that is formulated by the elderly themselves. Freedom of movement for the elderly should prevent social isolation and dependency. A demand-responsive personal transport system can improve the mobility of the elderly and increase their participation in economic, social, and cultural activities. This paper presents theoretical foundations of travel services together with some analyses that have been made with a demand-responsive shared taxi system, the OV-Tax Zoetermeer in the Netherlands.