The trade caravan post is makeshift shelter with a brahmin feed trough that traveling merchants will stop at when they visit the settlement. The traveling merchants that will visit are Trashcan Carla, Cricket, Lucas Miller and Doc Weathers.
The trade caravan post is located under Resources → Miscellaneous in the workshop
Trade caravan post (1)
Trade caravan posts can only be crafted in a settlement workshop.
This article is too short to provide more than rudimentary information about the subject. You can help Nukapedia by expanding it.