Stokenchurch Interchange is junction 5 of the M40.
Original layout prior to the M40 extension to Oxford. The underpass shown never existed during the roundabout's existence.
The junction opened as a roundabout at the western end of the former A40(M)
, now M40
. Space was provided for the motorway to pass beneath the roundabout on its way to Oxford although there would have been no west facing slip roads. When the motorway was extended westwards the junction was rebuilt as a diamond interchange
. Reasons for the alteration are unclear but the lack of provision for west facing slips may have been a factor.
In the 1990s had an MSA been built, the junction would have been rebuilt again as a dumbbell slightly to the west of its current location.