Transportation Models


SCAG develops and maintains state-of-the-art transportation models to support SCAG’s planning program. These models include:

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These models are applied by SCAG to forecast transportation conditions and resulting air quality.


Subregional Modeling

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The new Subregional Modeling Tool (SMT) greatly simplifies the creation of subregional models. The SMT fully automates the development of all aspects of a subregional model. The Tool is used by transportation commissions, counties, subregions, and cities wishing to create subregional models based on SCAG’s new Regional Model. The new Tool promotes model consistency between the Region’s various model agencies and greatly reduces the cost and effort required to create subregional models.


Heavy-Duty Truck Model

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Southern California Association of Governments (SCAG) developed the Heavy Duty Truck (HDT) model to evaluate important policy choices and investment decisions. The HDT model is a primary analysis tool to support the goods movement policy decisions made by SCAG and regional stakeholders.


Air Quality Modeling & Analysis

Air Basin in SCAG Region

EMFAC2007 is an emission factors model developed by the Air Resources Board (ARB) for calculating emission inventories for vehicles in California. This is the emission model approved by the Environmental Protection Agency (EPA) for calculating vehicle emissions for conformity purposes in California.