Why Rome's Roads Outlived Rome
The Roman road network ran to roughly 400,000 km, with about 80,000 km paved. Much of it was built for soldiers and mail, not trade. Two millennia later, segments still carry traffic — which says as much about institutions as about stone.
The engineering
A Roman road was built in layers: a graded foundation, gravel, then dressed stone set in a cambered surface so water ran off. Drainage ditches flanked the surface, and the whole structure was deep enough to resist frost heave. Deep, drained, cambered construction is a remarkably good answer to the problem of a road.
The maintenance
The network depended on upkeep: local labour, milestone markers, and a state postal system that needed the roads to work. When the empire stopped funding maintenance, roads did not vanish — they degraded, were robbed for stone, or were replaced by cheaper tracks. The survivors are often where later states kept repairing them.
What actually lasts
Infrastructure outlives the institutions that built it only if someone inherits an interest in it. Roman roads survived where medieval and modern routes reused them, and disappeared where they did not. It is a useful way to think about any infrastructure you rely on now.
Knowledge check
Two questions, no score
What most explains why some Roman roads still exist?
Now prove it