Application of Space-Time Prisms for the Measurement of Accessibility
The space-time prisms envisioned by Hagerstrand enclose the locations a person can reach by taking into account various time constraints. This concept has occasionally been used to measure accessibility, but was limited by data availability and computing power. Taking advantages of technological advances, a new procedure utilizing a geographic information system (GIS) is developed to locate facilities within space-time prisms. Data from Portland, Oregon, are applied to demonstrate how the proposed procedure can be used to measure accessibility to health care facilities. The potential of the procedure for measuring accessibility from the activity-based perspective is discussed.