Looks like they are modern to me. Note the ring highway around London and the routes going into Scotland.
The road going up the coast northeast looks like the enlarged (now) A 12 up to Ipswich. That the A12 keeps going up to, I think, Great Yarmouth.
Resided a couple hundred feet from that road as a
a teenager.
BTW, the A12 followed the medieval; middle ages route of a Roman road to Colchester or maybe beyond IIRC.
Some of the major Roman roads were in use in the original throughout most of the intervening centuries, with occasional repairs during the Middle Ages and Renaissance, into modern times, and finally paved with modern methods in the past 50 to 100 years. Those Romans knew how to build roads.
Ancient Roman road map unveiled
http://www.freerepublic.com/focus/news/1930916/posts
Archaeologists discover Britain’s longest road to be 10,000 year[s] old
http://www.freerepublic.com/focus/chat/3167705/posts
British Pre-Roman Roads Lead to Genesis (article)
http://www.freerepublic.com/focus/news/3085467/posts
‘Roman’ roads were actually built by the Celts, new book claims
http://www.freerepublic.com/focus/chat/3078474/posts
Iron Age road link to Iceni tribe
http://www.freerepublic.com/focus/chat/2764241/posts
What the Romans didn’t do for us
http://www.freerepublic.com/focus/chat/2733107/posts
Road sees first traffic for 1,400 years
http://www.freerepublic.com/focus/chat/1673842/posts
My reading of that map is that the current road system is on it, they put a dark line where the newly discovered Roman roads are. So the “ring highway” and “A 12” are modern roadways, not those that are unearthed.