Chittenden County Metropolitan Planning Organization (CCMPO) Travel Model Peer Review Report

Appendix E CCMPO Modeling Priorities

CCMPO Regional Transportation Modeling Priorities
March 22, 2011

Analytical tools to support transportation decision-making have long been a priority for CCMPO's Board of Directors and staff. The regional transportation model has gone through several iterations over the past ten years, most recently bringing us to a daily model updated with data from the 2009 NHTS Add-on for Vermont.

CCMPO will consider future model improvements within the context of what the MPO is able to fund and support. The TMIP Peer Review application included several issues of interest to the MPO which are roughly prioritized below based on a distillation of the peer review discussions to date and anticipated resources for modeling in the next Unified Planning Work Program of the MPO. Activity based modeling is listed as a longer term improvement, but CCMPO could still initiate work on certain aspects of this transition in an earlier timeframe.

Several of these issues are intertwined, but we have continued to maintain discrete points for each one to facilitate discussion and provide a more manageable approach to prioritizing potential improvements.Further refinement of these priorities will be based on feedback from the peer review process.

Short Term (1-2 years)

1. Modeling mixed land uses to support additional nonmotorized and transit use
   1. Many CCMPO policies and planning goals are supportive of mixed use dense clusters of land use and analytical tools which are sensitive to these characteristics are critical.
2. Improving air quality and climate change modeling
   1. CCMPO is participating in efforts to inventory greenhouse gas emissions and has a good chance of going out of air quality attainment for ozone. The transportation model will likely be used in concert with other tools (e.g. MOVES) to support analysis of these issues in the near future.
3. Reviewing sensitivity to increased travel costs (e.g. gasoline) in the model
   1. Gasoline prices are on the rise again and it would be very helpful to have guidance regarding how other regions are considering this in their regional modeling efforts.
4. Refinements to 1996 FHWA Quick Response Freight Manual truck modeling
   1. The current quick response based truck modeling approach used in our model generates a significant number of light truck trips (e.g. service and delivery vehicles) - about 100,000 or 13% of the total daily trips in the model. CCMPO is interested in examining this aspect of the model to see if a different approach or parameters are warranted for this and potentially other truck trip types.
5. Visualization techniques and performance measures for better communication to stakeholders
   1. CCMPO has used flow maps, measures of VMT, congested VMT, hours of delay, and other commonly used techniques to present model results to policy makers and the general public. Feedback from peers on any particularly effective measures or techniques to communicate modeling output to a broad audience is of great interest to the MPO.

Longer Term (2-5 years)

1. Recommendations regarding interaction/integration between model and microsimulation tools
   1. CCMPO has a number of corridor studies planned over the next few years. The regional model is expected to be used in most of these studies along with other more detailed capacity analysis tools, such as Synchro or VISSIM. One approach under consideration is developing a protocol to interact between TransCAD and the PTV Vision suite (VISUM and VISSIM). Another approach to this issue would be the use of Dynamic Traffic Assignment tools. Feedback from peers on the above or other corridor-level analysis techniques would be very helpful.
2. Transition to activity-based demand models
   1. There are compelling reasons to consider transitioning to an activity-based model approach, including the fact that RSG has already completed initial work on a DaySim implementation for Chittenden County related to a research study they received US DOT funding for. The increased complexity of preparing model inputs for future years is of concern to CCMPO staff. A review of the potential pros and cons of moving from a more traditional 4-step model to an activity based model from the peers would be helpful in determining where this change fits in with CCMPO's resources.
3. Expanding the model geography and integration with Statewide model
   1. This will be an ongoing policy discussion with our neighboring jurisdictions and will also require coordination with the Vermont Agency of Transportation and the University of Vermont Transportation Research Center. The feedback received in the first two peer review sessions has highlighted several issues to be studied on this topic. Any additional thoughts are welcome.
4. Recommendations regarding land use forecasting tools and existing LUAM
   1. Land use forecasting tools have not been a focus of discussion in the review process to date. Based on the brief conversation at the end of session 2 regarding this subject, CCMPO may pursue additional feedback outside of this peer process. Suggestions from reviewers regarding land use forecasting models or techniques which may be suitable for CCMPO and references to applications in other regions would be valuable.