🚀 Feature: Replace Transit Mode Choice Utility Expressions with Generalized Cost from Path Builder

[DavidOry]

User Story

In moving away from transit access points and to a zone-based transit assignment, the Emme path builder now generates a generalized cost estimate for each interchange (by access mode, by time of day). Skims from these paths are then returned to the mode choice model. The mode choice model applies a series of coefficients to the skim values to compute a second, different generalized cost used in mode choice. This is inconsistent and likely inefficient. It would be interesting to replace the mode choice expressions with the single generalized cost expression and see how the model performed. Other skims could still be brought in to make targeted calibration adjustments.

Progress:

• Sufficiently defined
• Approach determined
• Tests developed
• User story satisfied
• Doc strings
• General documentation
• Passing tests

Priority

Low

Level of Effort

Modest

Resolution Ideas

The mode choice UECs would be modified to replace the utility expressions with a reference to the generalized cost. The generalized cost from the transit skimming and assignment would need to be stored and skimmed. The mode choice models would then need to be recalibrated.

Project

No project in place yet

Who should be involved?

Users: @gregerhardt, @lmz, @FlaviaTsang
Reviewers: @DavidOry

Risk

Aside from moving the model out of calibration, the risks are low.

Tests

This is primarily a change to the UECs, so the tests would involve debugging the UECs to make sure they are being implemented properly.