In this paper the concept of individual action space is presented. The action space is defined as the area within the individual's farthest reach during a certain period of time. It is distinguished between actual and potential action space, the latter one being the area within the maximum distance attainable, subject to temporal and speed constraints. An action space model is presented. This model is related to previous accessibility models in geography, but it accounts for more complexity and wider differentation of choice and constraint conditions. Four variables are discerned: (1) the distance between the basic activity places (home, work place); (2) the travel speed; (3) the total time available; and (4) the travel time portion, which is the ratio between the travel time and the sum of travel time and sojourn (stay time). These variables determine together the individual's action space. The results show that the action space model is representative for types of actual action spaces. Some applications of this model are elaborated. (A)
Abstract