On show at the Design Museum in London’s Kensington is a small but fascinating retrospective on the work of Margaret Calvert, graphic designer. Ever wondered about how much easier it is to find your way on a British motorway than it is the ones on the Continent and in North America? Thank Margaret Calvert. Have you marvelled at the clean lines of the British Rail corporate style of 40 years ago and considered that it set a standard for all railway wayfinding in the decades since? Again, thank Margaret Calvert.