The 1920s were an incredibly important time for the UK's road network. Hard new surfaces were being provided at a rate never seen before or since, traffic surveys were being undertaken for the first time, and a brand new institution called the Ministry of Transport was doing strange things like issuing codes made up of letters and numbers to identify roads. Before the decade was over there would be hundreds of miles of new Arterial Road built in a road building boom to rival the motorway programme of the sixties.
There's another important milestone — if you'll forgive the pun — from the Ministry's activity in the 1920s that is much less well known. In 1920 they issued, for the first time, guidelines on the design of road signs, in an attempt to standardise the signs drivers would see and use nationwide. They were to be simple, uniform, and — above all — clear and legible.