Predicting Future Transportation Needs of Texas


ATG is proud to be the original architect and developer of four iterations of TxDOT’s innovative Statewide Analysis Model (SAM) for transportation systems across the State of Texas.

The SAM provides decisions-makers the ability to understand future travel demand and how transportation projects serve Texas’ needs. This multimodal model provides forecasts for highway passenger travel, freight transport, air traffic to and from Texas airports, intercity and high-speed passenger rail ridership, as well as freight rail tonnage and train forecasts.

In addition, the SAM provides TxDOT with on-demand forecasting and has been used to prioritize passenger rail corridors, produce performance measure for TxDOT’s statewide plan, contribute to ridership projections for the Texas-Oklahoma Passenger Rail Study (TOPRS), provide inputs for TxDOT’s Freight Mobility Plan, and provide traffic forecasts for project and corridor studies.

ATG continues to support TxDOT with updates to keep the model current with best practices, to take advantage of emerging technology, and to respond to new regulatory or analytical requirements. The ATG design incorporates both advanced and common-sense features intended to support analyses that lead to better planning for transportation solutions.

The SAM Version 4.0 (SAM-V4)  is the fourth generation of this state-of-the-practice model. The SAM-V4 update uses standard TransCAD 8 interface (similar to TxDOT’s MPO model interface), separate weekend modeling capability, increased geographic detail (all frontage roads in the state associated with IH facilities), the ability to forecast modal changes (air, rail, auto) for passenger trips that begin or end outside of Texas, the ability to run scenarios for any year between model base year and horizon year, and updated freight models based upon current observed data. Key enhancements to the passenger models include application of destination choice models representing all Texas related long distance passenger trips at a national level.