Roman roads relied on thickness and rigidity, and sometimes needed excavations up to 2m deep. This meant they were long lasting but allowed nothing for temperature induced expansion or contraction. They were consequently prone to surface fissuring and uneven drainage.
Vs:
The Chinese roads, on the other hand, were more akin to modern highways, being thinner and more elastic. They were built with a rubble sub-base onto which a layer of finely tamped gravel was added to produce a 'water- bound macadam'.
Other ancient road networks existed, but Rome and China were the big two from a civil engineering PoV.
Is that thing about 2m excavations actually true though? I read that it was actually a bit of a legend that started by somebody mistaking the construction process of foundations for villas with those of roads, and it just became assumed knowledge.
Obviously they were paved, but as I now understand it they were far simpler than the several layers I’d seen in history picture books in primary school! Otherwise the amount of material even a short stretch of road would need would be utterly impracticably huge.
From a civil engineering perspective, across thousands of km of Roman roads a statement like "and sometimes needed excavations up to 2m deep" would be true but uncommon.
( There's always going to be that vast length of bog, to long to justify going around, that needs crossing )
The main point here is that other large road systems existed at the same time as Roman roads.
See Also: https://en.wikipedia.org/wiki/Shudao https://www.newcivilengineer.com/archive/chinas-ancient-road...
Vs: Other ancient road networks existed, but Rome and China were the big two from a civil engineering PoV.