Supporting agile modeling through experimentation in an integrated urban simulation framework

Decisions regarding major urban transportation projects and land use policies are frequently political and controversial, as well as having significant economic, social, and environmental consequences. UrbanSim is a disaggregate, behaviorally-realistic modeling environment that planning agencies can use to simulate the long-term effects of such decisions. We describe UrbanSim’s evolution over the past decade from the perspective of supporting its appropriation by urban modelers, and identify support for experimentation as a key property that enables the adoption of an agile modeling methodology. Finally, we draw out three lessons for supporting agile modeling through experimentation: iterative development of models, providing appropriate domainspecific building blocks, and balancing the development of integrated tools versus interoperating with existing tools and the work practices that surround them.