Regional Travel Demand Modeling

COMPASS uses a travel demand forecast model to estimate average weekday and time-of-day demand for the transportation system in the Treasure Valley. The model can show where congestion may occur in the future, in addition to forecasted travel times and congested speeds. The model is used to test and help plan for future transportation projects, support local impact fee programs and master transportation / capital improvement plans, conduct air quality conformity demonstrations, support traffic impact studies by providing area of influence model runs for proposed developments, and respond to various other special member requests.

A major update to the regional travel demand model was completed in January 2015. Annually, the demographics and transportation network are reconciled to existing conditions and current programs and plans. Other model parameters and processes are refined periodically as necessary.

Model Geography and Characteristics (as of 2021)

  • Ada and Canyon Counties, Idaho
  • Population: 726,072 people (2020 Census)
  • Includes interstates, highways, principal and minor arterials, collectors, and some local roads for connectivity purposes
  • 2,489 Transportation Analysis Zones

Model Characteristics

  • Four-step trip-based model with feedback loop
  • Forecast four time periods – daily, 7 am to 8 am, 4 pm to 5 pm, and 5 pm to 6 pm
  • A household travel survey was conducted in fall 2011 to provide data for the model.
  • An additional household travel survey was completed in fall 2021 to provide updated data.
    • Calibration and validation of the model based on these results will be complete by fall 2023.

To request modeling services, please email [email protected]. Include your name and a detailed description of the request in the body of the email. Please note, COMPASS charges non-member organizations for special model runs. COMPASS reserves the right to deny any non-member special model run request.