On: How Metro Agencies Design the Letter 'M'

[MiddleEndian]

The Massachusetts Bay Transportation Authority has solved this one!

https://en.wikipedia.org/wiki/Massachusetts_Bay_Transportati...

[bewaretheirs → MiddleEndian]

Stockholm as well (with a nearly identical solution!) https://en.wikipedia.org/wiki/Stockholm_metro

[hammock → bewaretheirs]

In Chicago it's the 'L' (no lettermark that I'm aware of)

[kalleboo → bewaretheirs]

The MBTA T was actually designed with inspiration from Stockholm!

[qw → MiddleEndian]

Same as Oslo, but with a different color

https://no.m.wikipedia.org/wiki/Fil:Oslo_T-bane_Logo.svg