Mate, paved roads that the Romans built were
real constructions with a sub-basement and binding stuff between the stones plus reinforcements at the edges. - It is not the frequence on these roads or the weight of the frequence that "worked" on them and causes real destruction, it is mainly the weather and the nature in the whole.
Btw., we are modders who work on historical shaped mod projects since 2005.
Anyway, you've put a light on an area, reminding us to improve something, no doubt, thanks for that.
Honestly, a mod can always be improved, it is in principle the nature of a mod ( or for any game, otherwise there weren't modders

).
And therefor we have the suggestion and feedback thread (always sticked), so people can help us to improve released mods, because we don't or can't know everything.
I just took a look, and found that Charlemagne the Great (as the quasi western Roman successor leader) was probably the last souvereign for the Frankish realms, who had a real sharp focus on the existing trade roads, respectively mainly the old Roman ways. I've a list of these main long-range trade connections, and will list them soon in the dev forum as
discussion base. Because, there are no reliable sources (for me atm.) in how far they were still worth to be called constructed paved roads in the known Roman manner. In principle, we would need an in-between road type (between so-called dirt roads and Roman roads).
And hey, the Turkish road is built in the Renaissance, a completely other time with a far advanced science status about engineering and architecture. Especially concerning the static of constructions, and then "only" 500 years old, not around 1000-1400 years (Roman roads). It is really a wonder, that for example, the first paved road constructed by the Romans (the Via Appia) does exist still today.