I've made some edits in #80 to improve location assignment. One important thing to note:

• We should see improvement in assignment of primary locations. These are assigned a zone in 3.1_assign_primary_feasible_zones (see here and here)
• Assigning feasible zones for secondary locations is based on PAM here. The logic for secondary location in PAM is described in this notebook, and they use a combination of diversion factor, attraction of zone, and leg ratio. This approach does not guarantee finding a solution that matches the reported distance, as this is actually a difficult problem - you are constrained by fixed primary locations on either side. We should be aware of this when validating our results.

Potential future implementations (low priority):

• consider secondary location assignment when choosing primary zones (i.e we have a set of feasible primary zones, and we choose one that best fits our secondary zone constraints, but that is a very difficult problem and would require a rewrite of the pipeline workflow).
• Check the approach described in this paper