This lovely pair of images pops up on Getty Images, with no date or hint of a source. Any ideas?

“Fog Tricycles To Pilot Buses, Tricycles, fitted with fog lights and special red-lamps at rear, are now being tried out at Manchester to act as pilots for motor buses in foggy weather. They have only been in operation on one or two occasions but so far have proved quite successful. If adopted this may overcome the dislocation of services through fog. The tricycle as convoy to a bus showing the fog lamp in front. The tricycle gets through fog better than other types of vehicle. (Photo by Hulton Archive/Getty Images)