What is SPM?


SPM is a web-based scenario development, modeling, and data organization tool developed to facilitate informed and collaborative planning among counties/subregions, local jurisdictions, other stakeholders, and the public. Built on open source software platforms, SPM includes a suite of tools and analytical engines that help to quickly illustrate alternative plans and policies and to estimate their transportation, environmental, fiscal, public health, and community impacts. Moreover, SPM provides a common data framework within which local planning efforts can be easily integrated and synced with regional plans.


Senate Bill (SB) 375, which was passed by the California Legislature and signed into law by the Governor in September 2008, requires each Metropolitan Planning Organization (MPO) to develop a Sustainable Communities Strategy (SCS) for reducing carbon emissions. Under SB375, each MPO needs to provide the public with the necessary modeling information and tools for an informed assessment of the issues and policy choices in the development of SCS. Accordingly, in Spring 2011, SCAG developed the Local Sustainability Planning Tool (LSPT), a GIS-based sketch planning tool that allows users to create land use scenarios and analyze their impacts. Provided with preliminary scenarios of their planning areas, local planners were able to create, modify, and compare different land use scenarios and their subsequent impacts on vehicle ownership, vehicle miles traveled (VMT), mode use and GHG emissions. This allowed the local government participation in the development of the 2012 -2035 RTP/SCS to be far more fruitful than it otherwise would have been.

When SCAG initiated the 2016-2040 RTP/SCS process, additional functional and analytical needs were identified to better foster the creation of a highly realistic and implementable SCS through a “bottom-up” approach. After the thorough review of scenario planning models and tools in practice, SCAG joined other major Metropolitan Planning Organizations (MPOs) in California – Sacramento Area Council of Governments (SACOG) and San Diego Association of Government (SANDAG) – to enhance and customize the UrbanFootprint software system, a web-based scenario development and modeling framework built on open source software platforms and tools. Enhancement and customization of the UrbanFootprint system for SCAG’s application involves internal data development and scenario modeling capacity, local input and planning process across the region, and regional-scale planning and scenario development. In order to make the tool useful to subregions and local jurisdictions, SCAG formed a Working Group that includes representatives from all counties and subregions in the SCAG region to serve as an advisory group on functional and operational aspects of the model. Since its formation in 2013, the Working Group has been an invaluable source of support and guidance in the development and implementation of UrbanFootprint based SCAG Scenario Planning Model (SPM). 

Primary Purpose

The primary purpose of SPM is to enhance the Region’s ability to address complex issues and evolving challenges by providing better information about alternative future scenarios and by building an improved linkage between local and regional planning. SPM will provide local planners advanced capabilities and serve as a common platform for communication and collaboration between SCAG and local jurisdictions. Within SCAG’s integrated modeling and forecasting system, SPM serves as a conduit between local jurisdictions and key SCAG models, such as regional transportation models, land use/growth forecasting model and air quality model. The use of SPM, however, is not mandatory and is at the discretion of subregions and local jurisdictions.

Estimated Timeline

The first phase of SPM development focused on building a local-regional database connection through a Data Management site as a common platform and on setting up a Scenario Development and Analysis site for regional application. SPM Data Management site has been tested and refined through multiple rounds of pilot testing with select local jurisdictions from the SPM Working Group. The final Data Management site is available upon request until it is released to all local jurisdictions in the SCAG region in Fall 2017. 

SPM is currently in its second phase of development, focusing on building a local setup of Scenario Development and Analysis site with enhanced analysis modules. 

For frequently asked questions (FAQ) about SPM, click here.​​​​​​​​​​​​