Here’s an absolute gem, a surprisingly modern-looking diagram of trolleybus and tram routes in post-war London. Drawn by cartographer Fred J.H. Elston, the map employs 30-degree angles and radically straightened roads to great effect. All roads are clearly labelled, as are the different neighbourhoods of London, so orientation isn’t a problem. I also really like the way all the bridges are shown crossing the Thames: another effective orientation method.

Underground and main line stations are denoted by a small blue roundel and a black diamond respectively, though the lines between the stations aren’t indicated – which gives the outer edges of the map a bit of “connect the dots” feel with blue roundels seemingly just scattered around.

Even the route number bullets serve a purpose – each different colour and shape indicates which day different routes run on. For example, a white circle indicates a route that runs all day, while a red square means the route runs on Saturday and Sundays only. A blue square indicates all-night routes. Though I have to say that I’m a little confused as to what the difference between “Weekdays Only” and “Monday to Friday Only” is. There’s obviously some subtle thing that I’m not picking up on, but I’ve got no idea what that is.

EDIT: Thanks to those suggesting that in 1947 a “weekday” could mean Monday through Saturday; that could explain the difference.

Our rating: Seems to have more in common with modern best practices for transit diagrams than with something that’s now 70 years old. Quite wonderful: 5 stars.