Try thinking about what Roman roads were like...when they were actually Roman!
But for Ermine Street King Harold would not have made Hastings in the record time he did in 1066, even if parts had fallen into a state of disrepair. Think you underestimate the engineering emphasis the Romans put on the construction of arterial roads. After all, they were essential to commerce, military, and communication. Sorry would be happy to travel to Shrewsbury via Watling Street in the Roman era, plenty of hostels en route too. Fair chance of arriving safely, dry and probably mud free boots.