Section 7: Travel Demand Modeling Procedures
Anchor: #i1013660Review and Update
Federal regulations (accessible from a link on the TxDOT Internet at http://www.dot.state.tx.us/services/transportation_planning_and_programming/tpp_links.htm) require that MPOs and TxDOT review and update transportation plans at least every 5 years in attainment areas and every 3 years in non-attainment areas and Transportation Management Areas (TMAs). As a result, TPP now performs travel demand model updates on either a 5-year or a 3-year cycle (see Table 2-6).
|
Urban Area |
Non-Attainment Area |
Transportation Management Area |
Model Cycle |
|---|---|---|---|
|
Abilene |
No |
No |
5 Years |
|
Amarillo |
No |
No |
5 Years |
|
Austin |
No |
Yes |
3 Years |
|
Beaumont/Port Arthur |
Yes |
Yes |
3 Years |
|
Brownsville |
No |
No |
5 Years |
|
Bryan/College Station |
No |
No |
5 Years |
|
Corpus Christi |
No |
Yes |
3 Years |
|
Dallas/Ft. Worth |
Yes |
Yes |
3 Years |
|
El Paso |
Yes |
Yes |
3 Years |
|
Harlingen-San Benito |
No |
No |
5 Years |
|
Houston/Galveston |
Yes |
Yes |
3 Years |
|
Killeen-Temple |
No |
No |
5 Years |
|
Laredo |
No |
No |
5 Years |
|
Longview |
No |
No |
5 Years |
|
Lubbock |
No |
No |
5 Years |
|
McAllen-Pharr-Misson |
No |
No |
5 Years |
|
Midland |
No |
No |
5 Years |
|
Odessa |
No |
No |
5 Years |
|
San Angelo |
No |
No |
5 Years |
|
San Antonio |
No |
Yes |
3 Years |
|
Sherman-Denison |
No |
No |
5 Years |
|
Texarkana |
No |
No |
5 Years |
|
Tyler |
No |
No |
5 Years |
|
Victoria |
No |
No |
5 Years |
|
Waco |
No |
No |
5 Years |
|
Wichita Falls |
No |
No |
5 Years |
The modeling cycle is staggered such that during each calendar year approximately 5 urban areas undergo a travel demand forecast update. Approximately 6 months prior to the conduct of the five-year traffic counts, TxDOT notifies the MPO that the counts will be made. MPOs prepare the network data, trip generation inputs, special generator data, a TAZ to census tract table of equals, and the identification of TAZs considered to be CBD zones for the base and forecast years.
TxDOT performs the model calibration and validation and travel demand forecast for the urban area and provides the model output to the MPO. TxDOT also provides the network and trip table files to the MPO so additional alternatives can be tested.