Travel Demand Modeling

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Traffic on the roads results from individuals deciding where, when, and how to travel. Decisions such as where to live, work, and shop also impact travel behavior. A travel demand model is a set of mathematical procedures and equations that represent the variety of transportation choices people make, and how those choices result in trips on the transportation network.

TRPC maintains two types of travel demand models for Thurston County. The models have a base year of 2018, and a future year of 2045..  

  • Our regional model is a traditional 4-step model developed in the EMME platform. The base model update was completed in 2015. In 2017 the model was expanded to include all of Lewis County. The 2018-2020 update expanded the model to include all of Grays Harbor County.
  • Our regional dynamic traffic assignment model is developed in the Dynameq platform. This model covers Thurston County and parts of Pierce and Lewis Counties. Dynamic Traffic Assignment (DTA) models focus on route choice by simulating individual driver response to other drivers and roadway/intersection design and provide more realistic estimations of congestion and delay.

Request Travel Demand
Model Services

Download, fill out, and submit the Travel Demand Model Service Request Form (PDF) to or print and fax to (360) 956-7815.

Modeling Services

TRPC provides a range of modeling services for our members, their consultants, and non-members. Services range from a simple data requests for traffic counts or volumes, to building subarea models.
  • Members may receive most custom data requests free as a membership service. Large requests, such as building a subarea model, are arranged and paid for under separate contracts.
  • Non-members may need to reimburse TRPC for the costs of custom data preparation, unless the request is being made on behalf of a member.
Typical Model Data Requests

  • Traffic counts or traffic volumes (generally no charge)
  • Model file transfer (no charge for members or entities working for members)
  • Zone Distribution (for non-members, a two-hour fee is generally charged (contact TRPC for the rate) 
  • Select Link analysis (for non-members, a two-hour fee is generally charged 

Custom Model Services

  • Model development (for members or entities working for members only). Arranged and paid for under a separate contract.
  • Model analysis, future conditions or development scenarios (for members or entities working for members only).  Arranged and paid for under a separate contract.
Firms developing proposals to support our members may contact TRPC staff to discuss our custom model services.

Contact Us

  1. Aaron Grimes
    Senior Transportation Modeler

    Thurston Regional Planning Council
    2411 Chandler Court SW
    Olympia, WA 98502
    Ph: 360-956-7575