PSRC's travel modeling activities serve a variety of groups and various needs. This section outlines those needs and identifies the stakeholders in the regional travel modeling activities (this information comes mostly from an internal needs assessment document distributed to panel members prior to the meeting). In addition, this section describes the objectives PSRC has for the peer review based on those needs.
As part of PSRC's ongoing activities, they performed interviews with stakeholders in the region over the course of about one year. Through this process, PSRC identified a variety of needs. Model users were interested in seeing better model documentation, making the models easier to run, and getting better performance/speed from them. Several project types were of particular importance to stakeholders, including tolling and road user charges, transit system design, and operational improvements to highways. In addition, planning partners were interested in having web-based and interactive data products from PSRC's modeling group.
There are three key stakeholders of the travel model in the PSRC region:
Within PSRC itself, there are separate groups focused on long-range planning, short-range planning, and growth management. Government members include various city governments and planning departments and the region's transit agencies. The travel modelers include the Washington Department of Transportation, local municipal modelers and consultant firms.
The long-range transportation planning team is the primary user of PSRC's model, and they use the model for a variety of planning purposes. Tolling has been a hot topic in the region, primarily because it is not clear how the region will pay for maintenance of its existing infrastructure. The long-range planning team is very interested in being able to answer questions about the affect of road user charges on travel behavior.
This team also has a lot of interest in better understanding operational highway improvements, including ramp metering, incident response, traveler information, etc. They would also like to enhance the benefit-cost analysis capabilities to quantify congestion, health, freight, and social equity impacts of transportation decisions.
In the coming years, PSRC will be generating its first long-range plan for transit, and many transit-related questions are of interest, including the following:
Lastly, the long-range transportation team would like to better understand freight movements in the region.
The short-range transportation team performs air quality conformity analysis and relies on travel model run outputs of short-term runs. These analyses are typically needed about once or twice per year. A key requirement of the short-range team is model stability, since they need similar outputs from the travel model each time the analysis is performed. This can be challenging as model enhancements/adjustments are being made on a continuous basis, as modeling issues are identified.
The primary responsibility of the growth management team is to develop the region's long-range growth management strategy, name VISION 2040. This is a strategy developed on the basis of the growth vision of the region's stakeholders. This team relies on mode share estimates provided by the modeling team.
The model users group consists of agencies and entities that actively run the PSRC travel model. The users group typically meets four times per year. As part of the modeling needs assessment, a survey was conducted of model users. Figure 3‑1 through Figure 3‑4 summarize the responses of model users to survey questions.
Figure 3‑1 Most Common Transportation and Land Use Policy Questions in Near Future
(Source: Reference materials distributed by PSRC to peer review panelists.)
Figure 3‑2 Most Important Areas for PSRC Model to Be Improved
(Source: Reference materials distributed by PSRC to peer review panelists.)
Figure 3‑3 Typical Model User Applications
(Source: Reference materials distributed by PSRC to peer review panelists.)
Figure 3‑4 Model User Uses of Model and Inputs
(Source: Reference materials distributed by PSRC to peer review panelists.)
The survey also found that modelers that did not use the PSRC model typically did not because a smaller scale was needed for the applications of interest. A number of respondents suggested that model run times and performance were an issue that should be improved.
While formal goals for the peer review were not set prior to the meeting, it was clear that several topics were of particular importance and PSRC wanted feedback on those topics. In particular, PSRC invited guidance on building the travel model improvement program over the next few years, specifically advanced modeling components. Two key questions that PSRC had related to their activity-based model system, which has been operational for several months and is under testing, are:
PSRC was also very interested in getting feedback from panel members regarding a number of other topics, including the following:
