The B366 was a short road near Byfleet in Surrey, cutting off a corner between the A3 and A245. Originally its southern end was at a T-junction on the A3, which persisted even when that road was dualled. With the coming of the M25 the A3 was improved and the B366 now became accessible from the northbound A3 onslip.
This road is now a cul-de-sac only accessible from the A245, due to the HA closing the access from Wisley Interchange in the late 1990s (despite the strong and lengthy protests from every (Surrey, Elmbridge, Woking and Guildford) local authority in the area, Surrey Police and many Residents Associations).
Fifteen years on, many of the traffic problems at Painshill and on the Byfleet Road section of the A245 are, as predicted when this plan was first proposed, a direct result of this closure. It remains very sad that the HA resorted to closure, rather than fixing the weaving problems, as they did on the other side of the interchange, at the junction with the C43 to Effingham.