Virginia Transportation Modeling and Accessibility Program
Frequently Asked Questions
How Do I Obtain a Travel Demand Model from VDOT?
Please fill out the Travel Model Data Request Form (PDF, 99 KB) and return it to the Transportation and Mobility Planning Division of the Virginia Department of Transportation (VDOT).
How Do I Contact With Modeling Questions?
The contact information can be found here.
How Is It Determined When an Area Should Have a TDFM?
When an urban area reaches a population of greater than 50,000, a metropolitan planning organization (MPO) is designated for that area.
The MPO is a policy committee that oversees any planning activities for their region.
A TDFM is normally created for an MPO area as a tool to assist in the creation of the long-range transportation plan and an air quality conformity analysis.
Can I Use a TDFM to Conduct Individual Intersection Analysis?
Due to a travel demand model's regional scope and macro-level nature, it is not well suited for detailed intersection analysis.
Other "micro-level" modeling tools, such as highway capacity software, Synchro or VISSIM, would be better suited for this type of analysis.
Can Transit Ridership Be Represented in a TDFM?
In larger urban regions where transit ridership comprises a significant amount of commuter travel, a mode-choice model can be developed to help predict future transit usage.
The Washington, D.C., Hampton Roads, and Richmond/Tri-Cities models include mode choice.
Are HOV Lanes and Tolls Taken Into Account in a TDFM?
Where necessary, sophisticated models contain HOV travel and the effects of tolls on travel behavior.
Can I Get Bicycle and Pedestrian Information from a TDFM?
Because of their aggregate nature and regional scope, travel demand models do not forecast bicycle or pedestrian trips.