UrbanSim | ICOS

UrbanSim is a software-based simulation for urban areas, with tools for examining the interplay between land use, transportation, and policy. It is intended for use by Metropolitan Planning Organizations and others needing to interface existing travel models with new land use forecasting and analysis capabilities.

It is an open source urban simulation system designed by Paul Waddell (University of California, Berkeley) and developed with numerous collaborators. It has been distributed on the web since 1998 and Synthicity Inc. coordinates its development oand provides professional services to support its application.

The initial implementation of UrbanSim was implemented in Java and the software architecture was modularized and reimplemented in Python in 2005, making extensive use of the Numpy numerical library. The software has been generalized and abstracted from the UrbanSim model system and is now referred to as the Open Platform for Urban Simulation (OPUS), in order to facilitate a plug-in architecture for models such as activity-based travel, dynamic traffic assignment, emissions, and land cover change. OPUS includes a Graphical User Interface – GUI and a concise expression language to facilitate access to complet internal operations by non-programmers.

UrbanSim is designed to interface to existing travel modeling procedures, including both current four-step as well as newer activity-based travel models. It is currently being extended to address environmental impacts of development by simulating land cover, water demand and nutrient emissions. The model uses input data including population and employment estimates, regional economic forecasts, transportation system plans, land use plans, and land use policies to consider the complicated interactions between individual households; businesses; developers; and governments.

Outputs from UrbanSim include predicted residential and economic distributions, households, land uses by type, square footage of land use types, and prices of land. UrbanSim does not focus on scenario development, as most of these tools do, but rather on understanding the consequences of certain scenarios on urban communities.

One of the motivations for the UrbanSim project is to not only provide robust predictions of the potential outcomes of different transportation investments and land use policies, but also to facilitate more deliberative civic engagement in what are often contentious debates about transportation infrastructure, or land policies, with uneven distributions of benefits and costs. Initial work on this topic has adopted an approach called Value Sensitive Design.[

The first documented application of UrbanSim was a prototype application to the Eugene-Springfield, Oregon setting.Later applications of the system have been documented in several U.S. cities, including Detroit, Michigan, Salt Lake City, Utah, San Francisco, California, and Seattle, Washington. In Europe, UrbanSim has been applied in Paris, France; Brussels, Belgium; and Zurich, Switzerland with various other applications not yet documented in published papers.