A gantry spanning the motorway with blue overhead signs showing the following text.
Forward destinations: The NORTH, Stamford A1(M).
Exit destinations: A1139 Peterborough, Wisbech (A47); A605 N'hampton, Oundle [Hollow triangle diversion symbol] [Hollow circle diversion symbol].
Junction number: 17.
There's a free-flowing sliproad to carry you onto the A1139, part of Peterborough's extensive system of parkways, if that's where you're headed.