The Designation Sign Design
of the MFL

24 Jul 2023 • Outside

This was originally posted on cohost.

On the Market–Frankford trains of SEPTA in Philadelphia, the designation signs indicating the line and the next stop are very simple 18-panel 3×5-segment displays.

ALL STOPS - 69TH ST
ALL STOPS - 69TH ST

But they aren’t merely square segments! Each square may be subdivided into subsegments of triangles or quarter circles to give the the letters some ✨character✨, and so that some letters can actually fit within the grid. Taking a closer look at the segments, we can see the subsegment outlines.

N K

(The N and the K are two of my favourite letters in this set — I just think the design is clever.) Combining the outlines of a sample of letters, a single panel is subdivided as follows.

a three-by-five square grid further subdivided into subsegments. the four corners have quarter-circle segments. the middle three horizontally and vertically have an X dividing the square into four triangles. the bottom two left and right squares have mirroring diagonals through them inwards towards the middle going down.

This suffices to display all of the letters, digits, and punctuation needed by the MFL, which are all letters excluding J, Q, V, W, Z; all digits excluding 7; and the punctuation :, -, '. The letters are used mostly in the northeast Philly stations, which are, in order towards the northwesternmost terminus:

  • Spring Garden
  • Girard
  • Berks
  • York-Dauphin
  • Huntingdon
  • Somerset
  • Allegheny
  • Tioga
  • Erie-Torresdale
  • Church
  • Arrott Transportation Center
  • Frankford Transportation Center

You’ll notice a number of these are quite a bit longer than 18 characters in length. I was curious to see how they abbreviated those station names, so I took the train all the way to the terminus and took photos of each displayed sign.

NEXT: SPRING GARDN Spring Garden NEXT: GIRARD Girard NEXT: BERKS Berks NEXT: YORK-DAUPHIN York-Dauphin NEXT: HUNTINGDON Huntingdon NEXT: SOMERSET Somerset NEXT: ALLEGHENY Allengheny NEXT: TIOGA Tioga NEXT: ERIE-T'DALE Erie-Torresdale NEXT: CHURCH Church NEXT: ARROTT Arrott Transportation Center NEXT: FRANKFORD Frankford Transportation Center

York-Dauphin fits beautifully and fills all 18 panels; poor Erie-Torresdale has a third of its name abbreviated away; Spring Garden very nearly fits but does away with one letter (as does ALL STOPS - FRANKFRD).

From these signs, I’ve recreated all of the letters, digits, and punctuation used1, and also speculated on what J, Q, V, W, Z, 7 might look like. I’ve taken the J, V, W, Z from the San Francisco Muni Metro’s LRV4 designation signs, while I haven’t found a sample for Q or 7.

a grid of all 26 letters and 10 digits, a dash, a colon, and an apostrophe. they're in the style of the designation signs.

Personally, though, I would have made some of the digits a little more distinctive…

0 1 4
  • 0 contains a marking in the middle to distinguish from O
  • 1 has a hook and a foot to distinguish from I
  • 4 has a cut corner in the middle left to match the other digits

  1. I omitted because it’s identical to 1; yes, I know O is also identical to 0, ↩

 public transit  Philadelphia  MFL