Alamo Area Metropolitan Planning Organization
We plan to keep you moving!

Travel Demand Modeling (TDM)


The Alamo Area Metropolitan Planning Organization develops and maintains a full set of Travel Demand Models (TDM) for our region, covering all of five counties, including Bexar, Comal, Guadalupe, Kendall and Wilson. The current TDM, known as San Antonio Multi-modal Model, version 4.0 (SAMM4.0 runs in TransCAD 6.0) is currently being updated for better suitability in analyzing the air quality implications for various roadway and transit projects.  SAMM4.0 will be used for evaluating alternative demographic scenarios as well as alternative highway and transit systems as part of the Metropolitan Transportation Plan (MTP) update that will be adopted by our Transportation Policy Board in 2019. AAMPO’s TDM is a traditional 4-step model including Trip Generation (Tripcal5), Trip Distribution (Destination Choice), Mode Choice (Nested Logit) and Traffic Assignment (TransCAD MMMC User Equilibrium).  The SAMM 4.0 models now provide time-of-day forecasts for 4 daily time periods, including AM-Peak, Midday, PM-Peak & Overnight. 

Our Travel Demand Models provide the primary means for identifying existing and future transportation system deficiencies and for assessing proposed regional mobility improvements. The models are suitable for the following applications:

The current SAMM4.0 TDM has been calibrated and validated to travel data (including traffic count and transit ridership) for the year 2015, with a Short-Range Forecast for 2025, a Mid-Range Forecast for 2035 and a Long-Range (MTP) Forecast for 2045. Complete (or partial) sets of TDM downloads are available for each of these three analysis years including TAZ-level demographics, highway & transit networks, time & distance skims, trip matrices and a variety of model output summaries.

Please select a category of interest to you:

Download Modeling Data buttonDownload documentation button

If you have any questions or comments, please contact:

Zachary Graham

Senior Transportation Modeler
Travel Demand Modeling Supervisor

(210) 230-6907