So, back to the game where you spot certain road signs and let us talk about who came up with these iconic masterpieces… On 1 January 1965 a new road signage system became law. Where it was necessary to be able to read road signs and understand them whilst driving at various speeds.

Margaret Calvert was instrumental in making our road signs are as much a part of Britain’s landscape as London taxis and milk floats. Travel on any major road and the green and blue signs with their rounded white typeface are unmissable. Turn off onto a smaller road and the familiar red-bordered circles and triangles with their black silhouetted figures mark the way.

When Kinneir was appointed head of signs for Britain’s roads, he hired Calvert to design the signs. She designed easy-to-understand icons which at the time were revolutionary, including the signs for ‘men at work’ (no, not a man and his umbrella!) and ‘farm animals’, which she based on a cow named Patience that lived on a farm near where she grew up.

The Transport and Motorway typefaces were devised by Kinneir and Calvert, which is used only for route numbers on motorways, are still the only two typefaces permitted on UK road signs. Transport is also used in several other countries, including Iceland, Ireland, Portugal, and much of the Middle East.

Along with the typeface and the images, Kinneir and Calvert also created rules for the traffic signs that continue to be used today. For example, the wide gaps in letter spacing are derived from research the pair conducted on how type should scale according to the speed of the traffic passing it. For the road signs, the unit of measurement for spacing is based on the width of capital ‘I’, a consistency that the designers say helped forge a sense of familiarity among drivers.