Claude Johnson, Dictionary of National Biography… (1912)
“ The traffic legislation at the time forbade self-propelled vehicles to travel faster than four miles an hour, and a man carrying a red flag had to precede them on highways. On procuring his car Rolls set out from Victoria station, London, for Cambridge, and was stopped by a policeman owing to the absence of a red flag. He made the journey to Cambridge in 11 3⁄4 hours — travelling at 4 1⁄2 miles an hour. In Aug. 1896 the Locomotives on Highways Act freed motor traffic of some of its restrictions. ”
