Everyone: (update 9/9)
The most important letter additions - to SUPPLEMENT existing graphics and color coding - would be:
-M- Market-Frankford Line
-B- Broad Street Line
-N- Norristown High Speed Line
-E- Media Rail Line
-S- Sharon Hill Rail Line
-P- PATCO High Speed Line (if PATCO agrees to go along with the proposed SEPTA letter designation scheme)
The five Subway/Surface routes can have either their own single letter designations or use Ta, Tb, Tc, Td and Te.
-O- Overbrook (10); -R- Darby (11); -Y- Yeadon (13); -A- Angora (34); -W- Eastwick (36)
From AC's input -G- would replace 15 for the Girard Avenue trolley route.
The letter -D- is already in use for the Boulevard Direct limited express bus service.
An idea can be to designate this service with -BD-
For letter designations to represent rail routes or special services the seven SEPTA bus routes that have letters
(PTC holdovers) should be changed to open or unused numbers under 90 to complete this "divide":
Routes G, H, XH, J, K, L and R (this could be implemented with future bus route changes proposed)
These are open numbers - seven would be needed: 41, 51, 63, 69, 71, 72, 74, 81, 82, 83, 85, 86, 87.
In closing letters should add additional identification for rail or special routes.
Numbers can identify bus routes...MACTRAXX
EXPRESS TRAIN TO NEW YORK PENN STATION-NO JAMAICA ON THIS TRAIN-PLEASE STAND CLEAR OF THE CLOSING TRAIN DOORS