The most strict restrictions and speed limits were imposed by the 1865 act (the "Red Flag Act"), which required all road locomotives, which included automobiles, to travel at a maximum of 4 mph (6.4 km/h) in the country and 2 mph (3.2 km/h) in the city, as well as requiring a man carrying a red flag to walk in front of road vehicles hauling multiple wagons.

[citation needed] New steam powered road locomotives, some up to 9 feet (2.7 m) wide and 14 tons, were alleged to damage the highway while they were being propelled at "high speeds" of up to 10 miles per hour (16 km/h).

[2] It has been claimed that the restrictions in the earlier act were advocated by those with interests in the UK railway industry and horse-drawn carriages.

It was feared that engines and their trailers might cause fatal accidents, scare horses, block narrow lanes, and disturb the locals by operating at night.

[4] The emerging UK automotive industry advocated very effectively for the 1896 Act during the preceding year.

[5][failed verification] Economic historian Kenneth Richardson has suggested that the 1896 Act may have been written by Sir David Salomons, the founder of the Self-Propelled Traffic Association, on his assumption that no government department personnel would have had the necessary experience to do so themselves.