They should look at YVR, where they renumber the gates every 2 years or so
I don't know why a line built as Evergreen Line has to be run as Evergreen Line.. There are many places where the line operations is different than how they were constructed.
Just to give some example:
- Calgary's Northwest Line and South Line together forms the 201 (red) route; Norheast Line and West Line forms the 202 (blue) route. You still hear "Northwest Line Extension", it really means an extension to the 201.
- Toronto merge Yonge Line, University Line, and Spadina Line in to a single route; Bloor Line and Danforth Line into another.
- Seattle have Central Link, Airport Link, University Link, Northgate Link, Lynnwood Link, South Link, Tacoma Link, ... so many different names but its just a single route.
- Each of the line in New York Subway has their own name, but they rarely run independently on their own. For example, the multi-billion Second Avenue Subway project won't gets its own line for a long while - they just going to redirect the north section of the the Q train (BMT Broadway Line). They spent 4.5 billions on it but not going to keep the name as an independent line.
- Each of the route in Chicago L is made up of many different lines. For instance, Red Line is made up of a combination of North Side Main Line, State Street Subway, and Dan Ryan Line; Blue Line consist of O'Hare Line, Milwaukee-Dearborn Subway, and Congress Line.
Perhaps it would be less confusing if we call it the "Yellow Line" or the "M-train" or the "BME-line", but it would be standard to have the "Millennium Train/Line" that through run the Broadway Subway, Millennium Line, and Evergreen Line..