Planning Support Systems Evolving: When the Rubber Hits the Road

Planning support systems (PSS) have moved from concept to application. One of the core assumptions of PSS is that these computer-based systems can be applied in actual planning situations and found useful as decision support tools. Based on previous experiences with applied computing efforts, we need to think carefully about how best to support successful implementations of PSS. Lessons can be learned from both experiences with large-scale urban models and with the four-step urban transportation planning process. We examine the potential of PSS across four dimensions — data availability, acceptance and support, ease of use, and appropriate and useful output.