The Alliance team has worked with the state of Arkansas on a number of related projects designed to assist with transportation system planning and analysis. Our planners developed two versions of the Arkansas Statewide Travel Demand Model (AR TDM) and, subsequently, participated as part of a team that developed the Arkansas Long Range Intermodal Transportation Plan (AR LRITP).
Our work on the AR TDM has benefited the Arkansas State Highway and Transportation Department (AHTD) in creating solutions for their transportation system. The AHTD has used the model for planning and analysis to prioritize large scale highway infrastructure investments in specific intercity corridors, as well as to forecast and analyze transportation system performance under various growth and economic scenarios.
Leading a team of national consultants, Alliance initially created Phase I of the AR TDM as a three-step model with trip generation, trip distribution, and trip assignment. Incorporating freight travel and a feedback loop between traffic assignment and trip distribution, the first phase of the AR TDM was designed to allow a passenger mode choice model to be incorporated into the second phase.
The statewide travel demand model included a level of detail typically reserved for an urban area model and freight forecast by mode.
Alliance was then selected in January of 2013 by AHTD to develop Phase II of the AR TDM. The work generally consisted of creating a future year 2040 network, updating the 2009 base year network, and providing an analysis component for various modal scenarios.
Phase II of the AR TDM added an advance passenger mode choice component that allows AHTD to forecast ridership for urban rail lines and urban bus routes. The AR TDM includes all fixed transit routes in the state.
As part of our modeling work, the Alliance team also:
- Specified the model architecture
- Updated TAZ geography
- Updated the transportation network
- Updated socio-economic data
- Updated the model interface
- Estimated and validated a passenger mode choice model
- Updated the freight model specification and validation
Given our success with the AR TDM, we were also selected to participate as part of a team that developed the Arkansas Long Range Intermodal Transportation Plan (AR LRITP). The Alliance team’s role was to forecast travel for several scenarios using the statewide travel demand model (AR TDM) we helped develop.