Survey work being carried out at Newstead, 50 miles north of Hadrian's Wall, has led to the discovery of what appears to have been a 60ft (18.28m) long, 12ft (3.65m) wide traffic island, just inside the entrance to the 1,900- year-old military base.
The discovery - by archaeologists from Bradford University funded by the National Museums of Scotland - suggests that traffic into and out of the fort was sufficiently heavy to warrant some mechanism to split it up into outgoing and incoming.
If there were indeed large numbers of carts, chariots and pack- horses leaving and entering the fort, then there would probably have been traffic chaos without some sort of road island or central reservation.
Newstead - known as Trimontium after the three hills that overlook it - became the largest Roman fort north of Hadrian's Wall.
In the second century the fort developed into a small town with up to 2,000 inhabitants.