Question: How do you decide on the overall dimensions and aspect ratio when creating a new map?

Answer: For my personal map projects, the aspect ratio is the first thing I decide upon. I generally try to stick with standard formats that are compatible with framing – these being 1:1 (square), and 3:2 or 4:3 rectangles. 

Generally, I use 3:2 the most – 36″ x 24″ and 24″ x 16″ are great finished sizes and the aspect ratio works nicely for a lot of maps. I do try to work as closely as possible to the final size of the piece, as it allows me to judge whether elements like labels are going to be legible when I’m done.

Of course, real world transit maps often have their size and aspect ratio determined by the location that they’re going to be used at. Boston’s MBTA map is a square because the signage at stations is divided into three square panels, for example.