itinerary pillar
A pillar serving as a guidepost at the meeting of two or more roads, and, more especially, one having the distances to different cities inscribed upon it. The term is generally limited to such pillars in classical Roman usage, and this because of the Roman itineraries or official descriptions of the roads through a province or a section of the empire, upon which chartlike records the pillars were clearly marked. (Sturgis, 1900)