Scenarios are built upon a base-year canvas that provides a baseline assessment of the existing conditions, including land use, demographic characteristics, roadway and transit, land types, environmental features, and others. SPM streamlines the development of the base canvas through scripts and processes that normalize data of varying quality, type and scale from a wide range of sources. The base canvas provides the context for scenario painting and editing, and subsequent analysis. Once the base canvas is set, scenarios can be created in two ways: translation of existing plans, and ‘painting’ or editing of new or existing plans or scenarios.
Existing Plan Translation
SPM analyzes existing plans or scenarios at any scales based on their key characteristics such as density, mix of uses, and street connectivity. It then translates each geographic area (e.g., parcel, TAZ, or SPZ) of the input plan into one of the model’s common language of Place Types, which represent a full range of existing and future land development patterns, from urban mixed use centers, to employment and industrial areas, to standard suburban residential areas that can be seen across the SCAG region. This allows SCAG to integrate local plans together into a common regional fabric of land use and transportation plan and to perform consistent analysis on individual plans or combinations thereof.
Scenario Painting and Editing
SPM’s web based scenario painter that includes a suite of selection adn viewing tools allows the user to edit or build upon a translated plan or scenario, or create new scenarios from scratch by applying Place Types to the landscape. In addition to various spatial data layers available via SPM’s graphical user interface, ranging from parcel level land use, to statewide resource areas and farmland, the web based scenario painter can also display regularly updated data available on the web today (e.g., Google Maps, Open Street Map).