A blue sign with a diagram showing a branch off the road ahead and the following text.
Forward destinations: The NORTH; Luton & [Airport symbol].
Exit destinations: (M25); St Albans; A405.
Junction number: 6.
Change Route: A405 (M25)
This is the junction for the North Orbital Road, a sort of 1930s precursor to the M25. Exit here and head east for a short hop to M25 J21A.