Adding Logsums

Getting Started

• Scope of Work
• Will start by implementing just the work location choice model logsum needs in order to draft a vectorized approach
• Will create two new model steps and revise the existing step:
  • workplace_location_sample - will use a similar expression file as today (but without the logsum expression), but will build a table of workers * all zones in order to select a sample of alternative work locations for the next model. This selects 30 locations from the 1450 zones. It does 30 picks and returns the pick count as well, since this is used in the later model step as an alternative correction factor.
  • workplace_location_logsums - will start with the workers * sampled alt zones table output above and will add home taz, alt taz, depart period (which is set to 8 am), end period (which is set to 5 pm), and will add a logsum column (see issue below)
  • workplace_location (existing) - will start with the table output above and the existing expression file in order to choose a work location like before. This step selects one location from the sample of 30, this time with the mode choice logsum included.
• The mode choice model will be revised to add new capabilities to get logsums in addition to making choices. The current mode.tour_mode_choice_simulate function adds a choice mode column to the choosers table (tour). We need to add a method to add a logsum column to the choosers table (tour) as well. #164