Project Meeting 2021.01.19

Technical meeting

• Update from Joe on the bench contract

  • May be a bit awkward for one of the consultants to bid on task orders and set the agenda
  • Will likely have an owner's agent task order to continue to help administer the effort
  • This may end up being a bridge solution for the time being
  • @Joe to share draft scope for next round of work with the partners to discuss
  • Includes removal of orca and other draft 6b work items

• Update from Doyle on performance issues profiling and PSRC support

  • Setup and ran PSRC example
  • Went ahead and multiprocessed accessibility since it was quite slow for PSRC and it was sort of already working
  • Run times went from something like 5 or 6 hours to 20 minutes
  • PSRC to test; code on the develop branch
  • Need to setup and run ARC next and then profile

• Update from me on location sampling improvements design ideas

  • Jeff and I discussed the issue in detail and have two approaches that we're considering
  • Chooser approach and matrix approach
  • For chooser, location_sample always runs at the TAZ level
    • And size terms are aggregated to TAZ level when first calculated
    • n TAZs are picked (say 30) and then an MAZ for each TAZ is picked based on the MAZ's share of TAZ size term
    • In addition, we de-duplicate the calculation within chunks to save on runtimes and we also sort by origin zone to increase the amount of de-duplicate
    • Fits well with existing design and hopefully is fast enough
  • For matrix, we do the calculation as a pre-computed probability matrix by market segment
    • Users need to configure ahead of time and then reference in expression files
    • We need to build new data structures that are persisted? and referenced through the system
    • Expression files are OD level rather than chooser
    • Is just the number of calculations that are required + probability lookups with random numbers to make choices
    • May require more code changes and may not be as flexible moving forward
    • For estimation integration, we'd need to convert the outputs to a chooser like format or update the larch code to handle the matrix
  • We're still thinking it through, but we're hoping the chooser approach will be ok
  • Stefan drafted a quick chooser style approach and its runs quite fast so this approach may work just fine
  • For ActivitySim, we're often charting a course that draws from the hard-coded/fast DaySim approach and the UEC/slower/but more flexible CT-RAMP approach. This is a good example.
  • All software moving forward should support:
    • estimation
    • documentation
    • tracing
    • multiprocessing
    • multiple zone systems

• Update from Newman on estimation enhancements

  • Plan to work on it this week

• Planning for Joel to join next week's call to share the draft transit pass model design

  • Let's share the plan (or outline) ahead of time so partners have time to review
  • We need a generic model that can be used in multiple regions - not just a model for semcog

• Update on telecommuting

  • Model programmed and being setup for semcog now
  • Is this being used in mode choice? Not yet. Any downstream model can be conditioned with the new person variables though
  • Partners planning to discuss getting better example data together for a more realistic example

• Update on draft agreements shared

  • Plan to discuss again Thursday
  • New MOU solves everyone having to re-sign when a new partner joins
  • Funding agreement explains what you are paying for
  • The term of the agreement is still undefined
  • Want to get everything executed by July 1
  • Please review as soon as you can
  • Alex to share his comments