Why This Tiny Lane Allows 60 mph

From the video's description

That white sign with the black stripe has no number. On a lane one car wide, it still means 60 mph.
Until 1965 it meant something else: outside towns there was no speed limit at all. In June 1964 a race car on a Le Mans test did a reported 185 mph on the M1, and nothing unlawful had happened. After pile-ups in fog, a 70 mph limit came in on every open road on 22 December 1965, and the old sign stayed to mark it. Single carriageways have been at 60 mph since 1977, and every lane without its own lower limit got the same number.

Sources

roads.org.uk "To the Limit" (history of the derestriction sign and the 1965 limit); Autocar, "The day Jack Sears hit 185mph on the M1 motorway"; House of Commons briefing SN00468 "Speed limits in England"; Highway Code rules 125, 126, 154, 155; GOV.UK speed limits;
DfT Reported Road Casualties Great Britain 2024.

Main photo: "Flat out in a tractor?" (Sandy Lane, near Stanton Drew, Somerset) by Neil Owen, geograph.org.uk/photo/5025466, CC BY-SA 2.0.
3D: "Land Rover Defender 90 Lowpoly" by kekis69, "1962 Ferrari 250 GTO" by Dave Love (shown unbadged as a generic 1960s racer), "Tall Grass Elegance" by endlishem, "Mighty Oak Trees" and "High Detail Elm Tree Collection" by Jagobo, "man sitting" by Ace-of_spades (all CC BY 4.0);
plants and textures from Poly Haven (CC0). Sounds: Freesound CC0 (EverydaySounds, flumpytripod, BenDrain, kyles, loganzsound, richwise, NickPeeters, bonehead, conleec) and the channel's own.

UK traffic sign designs: Crown copyright, Open Government Licence. Car makes and logos shown belong to their owners; no endorsement.