Project Meeting 2022.08.25

Agenda

• Admin items
  • New docs includes versioned history, feature branch capability
  • End testing with Travis, migration to GitHub Actions is ready
  • Need for additional data validation checkers
• School escorting code review - postponed topic
• Shadow pricing update

Meeting Notes

Shadow pricing update (approach and implementation)

• Presentation: RSG_revised_shadow_pricing.pptx
• In destination choice, shadow pricing is a constant to doubly constrain the model. This is a simulation-based approach.
• Scaling term in order to account for the fact that workers does not equal jobs in the model inputs
• Added shadow pricing settings in a new yaml
  • Set method: “method3” but name could be changed
  • Set the land use file fields for scaling
• Shadow_pricing.py includes the iterating and most of the shadow pricing code
• Location_choice.py includes the sampling process
• Status
  • Code is mostly in place
  • Tested with a small sample from a 2-zone system
  • Currently running without errors
  • Number of workers to simulate plateau at iteration 4, 5, and 6 due to multiprocessing – currently testing without multiprocessing
• Questions
  • Since shadow prices cannot be estimated, and calculating new shadow prices can be time-consuming in terms of computational time, should shadow prices be updated when the modeled transportation improvements are significant enough to modify the usual workplace distribution?
    • Judgment call
    • Purpose of this process to make it faster so it’s easier to rerun if needed
  • Tests after implementation: how do things change iteration to iteration and in the end, look for potential bias. Metrics could include:
    • Compare flow from old method, new method, and observed
    • TLFDs, average trip lengths
    • Segment by zone size
    • There is documentation about this process but maybe not enough detail on the tests, could be expanded if requested