Start with the routes people actually use.
Bring a lot diagram or aerial view to your site review. Mark entrances, exits, drive aisles, loading doors and the crossings between parking and the building. A retail lot with customer traffic throughout the day needs different priorities from an office lot with a concentrated morning arrival.
Identify areas that must remain accessible while other areas are being cleared. Opening hours, occupied parking and delivery windows help define the proposed sequence. These priorities belong in the written scope, not just in a conversation during the first storm.
