CURRENT UPWP   //  Travel Demand Model Improvements 2023

Travel Demand Model Improvements 2023

In 2020, the APO undertook an effort to significantly update and improve its Travel Demand Model (TDM), including building into the model updated algorithms and other improvements based on more state-of-the-art research and data regarding TDMs. As part of those updates, the model structure was altered to allow for time-of-day distribution of trips rather than just total daily trips. However, the budget at the time did not allow for the time-of-day distribution of trips to be fully implemented. Therefore, we are budgeting additional funds to

  1. fully implement the time-of-day distribution of trips, and
  2. Insert the necessary script to allow select-link analysis of model output.

Understanding how many trips use a particular corridor at specific times of day – such as the peak travel times – will allow the model to better inform corridor studies and lead to more efficient distribution of resources.

We expect the time-of-day distribution of trips within the model to be based on actual measured traffic volumes within the APO planning area. The current model will provide time-of-day traffic counts, but they are not actually calibrated to anything. We strongly prefer that the model output be based on measured, real-world data.

The APO does have access to Streetlight data and can provide data and information from Streetlight to the consultant for use in this effort.

The daily trip count model output should be the sum of the traffic counts from the various times of day.

The times of day used in the model can be grouped into logical bins, such as:

  • 6 am – 8 am
  • 8 am – 11 am
  • 11 am – 1 pm
  • 1 pm – 6 pm
  • 6 pm – 6 am

…or whatever bins seem most logical while still being insightful in a corridor study, understanding peak-hour traffic versus off-peak traffic, and as potential inputs into a microsimulation model.

If interested parties need access to our TDM files in order to ascertain the level of effort that would be needed to accomplish the goals of this proposal, you can send a request to

Related Planning

The model improvement effort in 2020 resulted in a series of technical memos that discuss our model structure and operations in detail. They can be found here:

Our 2022 TDM calibration report can be found here:

What’s Happening Now?

The APO received three proposals and ranked them in priority order. We have successfully contracted with the top-ranked firm, SRF Consulting Group. This project has kicked-off and the consultant has begun work.