Project Meeting 2022.02.22

Agenda

1. External Trips Component by RSG/SANDAG
2. Discussion of Meeting Format

Notes

Admin Items

• Recording today, and meetings from now on. Teams will store the recordings for 60 days, contact Jeff Newman ([email protected]) or Michelle Bina ([email protected]) for access to recordings as needed.
• Meetings page on the wiki will contain outline of upcoming meetings

Internal/External Models

Presentation Slides

• ActivitySim currently only addresses internal travel destinations

• Concerns about double counting travel, especially for those near model boundaries

• Estimation of components starts next years

• Questions about the characteristics of people making the I-E travel, need to look into survey data

• Explanatory variables in generating I-E travel

  • Whether or not to generate I-E travel: distance to external station and size of external station are likely, but will find out during estimation
  • External station destination choice model: logsum generated to each external station (size is function of forecasted traffic at external station)

• How do HPMS adjustments factors play into this new structure?

  • SANDAG doesn’t use HPMS for model calibration
  • Caltrans publishes VMT data, they use that as a target
  • They do some adjustment on the CV side, but model is pretty close to VMT targets, so they don’t adjust on the person travel side (use trucks as the dial to adjust)

• Implementation

  • Currently "extensions" but will likely move to components in ActivitySim
  • Leveraging the regular workplace location choice models but reduced set of persons
  • Internal models are not running for external workers and students
  • Still working on utility expressions, pushed until after estimation
  • Still working on how to include size terms
  • Input csv with control total of work and non-work vehicle trips for each external station

Question for moving forward: when other developers want to add something, should it be an extension to import or a modification the core?

• How to make software smart, to understand what’s in the pipeline – something that says if you don’t have this component, you shouldn’t have these downstream components/variables that go with it
• PARKING LOT ITEM: What’s accepted upstream and what should you use downstream
  • Systematic modularity – need to understand extensions versus components
  • A practical example is long-distance model, which would only be used for statewide or megaregion models
  • Jeff to put together information about costs/benefits of how to do this
  • Is ActivitySim a toolbox, allowing the user to customize – or do we want to be curators with recommended packages that allow minimal customization?
  • Other components being developed for SANDAG: visitor component and ground access models

Upcoming Meetings

• Thursday 2/24/2022: Sharrow
• Tuesday 2/29/2022: Vehicle Types Model

Twice a week at the beginning of Phase 7, to kick off new tasks, then once a week when there is a lot of work going on and not much deliverables to present

Smaller group meetings for deep dive on components? We will think about this.

There is interest in keeping Thursday as dedicated meetings regardless.