Regional Forecasting (Control Totals)

ARC Regional Model--REMI

In 2007, ARC began reviewing forecasting models to develop new control forecasts for population and employment through the year 2040. ARC selected REMI. Learn more about REMI by viewing the Policy Insight Introduction (PDF), and get even more in depth by reading the User Guide (PDF).

In 2009, ARC used REMI to generate a new set of regional control forecasts. A Technical Advisory Committee (TAC) of local economists (Brief bios here) reviewed the Policy Insight forecasts and a general agreement on a reasonable forecast was reached in April. ARC staff then began allocating the regional controls to smaller geography.

Read the Regional Snapshot about the regional forecasts.

Small Area Forecasting (Land Use Allocation)

ARC Small Area Models-- TAZ-D and PECAS

Also in 2007, ARC began reviewing state-of-the art land use models to allocate the forecast population and employment totals to small areas.

A short-term bridge, called the TAZ Disaggregator (TAZ-D)  was used for small area forecasting in the Plan2040 process. More detailed information on TAZ-D can be found on the Documentation webpage.

For a long-term soultion, ARC chose PECAS (Production Exchange Consumption Allocation System), which is currently being used in Oregon, San Diego, Baltimore, and California. See below for more information about PECAS.

PECAS Timeline: 
2008-2009: Technical Advisory Group (TAG) met three times to review and refine the model’s development framework.

2009-2010: Uncalibrated model developed and initial scenario analysis completed.

2010-2012: Three additional phases of PECAS model development and calibration occurred or are ongoing, including a partially-calibrated model running “through time” (iterative runs). 

The “end goal” is a small-area allocation model that provides a consistent and defensible projection of land use for the next long-range plan update (est. 2014-15 delivery date). This model will be linked to the new “Activity Based” travel model that ARC has under development. 

Economic Modeling for the Transportation Referendum

The Plan 2040 effort led to a demonstrated need to identify alternate mechanisms of funding short-term improvements to “jump start” infrastructure enhancements in the transportation planning area. In 2010, the Transportation Investment Act (TIA) sales tax concept became the designated “targeted” mechanism for funding. The goal then became the development of a project list on which revenues of the contemplated sales tax might most optimally be spent.

ARC augmented the REMI model with REMI's Transight to assess the economic impact of the transportation projects included in the Regional Transprotation Referendum, which will be voted on July 31, 2012.

Results of the economic modeling can be found at the Regional Roundtable website. Also, read about the economic impacts and the travel impacts of the Regional Transportation Referendum.

For more information about the PECAS model:

For more detailed information about PECAS, visit any or all of the following resources:

Short theoretical outline (PDF)
Definitive theoretical framework (PDF)
Input Output Accounts in a Spatial Framework (PDF)
A Presentation by Dr. Doug Hunt on PECAS (PDF)
A Diagram of the Activity Allocation Module (JPG)
A Diagram of the Space Development Module (JPG)
Floorspace Synthesizer Overview (PDF)
Calibration of Floorspace Synthesizer (PDF)
Parcel Synthesizer Diagram (PDF)