In-place Replace feature

Wait, aren’t you talking about his “Replaced selected” feature available in context menu of actor placed in world?
You need select a new actor/mesh in content browser and then it will appear at “Replace Selected Actors with”.

Putting a static mesh component into blueprint would allow you for one-click replacing all instances, but it adds overhead of blueprint actor…

Other alternatives:

  1. If you’d put all the road fragments into the same folder in World Outliner, you can easily select them all and change mesh in actor properties.
  2. Maybe using instances would be useful for you? Instance Tool in Code Plugins - UE Marketplace