Aerial flood mapping technology has been used by amateur archaeologists in Britain to discover seven previously unknown segments of Roman roads built in the 1st through 4th centuries. The Roman road network in Europe, North Africa and the Middle East was the largest in history until the construction of the U.S. interstate highway system which began in the 1950s. As you can see from the map below most of the newly discovered roads are in the north of England. What a thrill for these amateurs who, in some cases, have spent decades looking for lost roads!
(From Daily Mail Online)
Below is a previously identified segement of Roman road in the same general northern region.
If you are interested in a brief (21 second) overview on how the Romans designed their roads watch this. If you have more time you can watch a 40 minute National Geographic special on the roads right here.