Hey Cameron,

We could use official_name=* but personally I'm not too sure of the value. Generally my gut feeling is that there isn't much use duplicating data from TTC GTFS that isn't directly used in OSM itself. So name=* yes, route relations maybe (some apps do use them), but official_name=* probably not? The most useful parts are probably name=* and ref=* which contains the TTC stop ID which matches GTFS stop_code.

GTFS guidelines in OSM were recently approved, you can take a look at https://wiki.openstreetmap.org/wiki/GTFS  - it's a bit Euro-heavy, but my gist is we can add gtfs:stop_code=5425 to tie stops to GTFS (or just use ref=*, but I guess gtfs:stop_code=* is more explicit) and maybe gtfs:route_id=61394 to routes to tie them to GTFS. That might be useful to someone at some point.

I'm mixed on the "west side" thing for farside stops. Part of me wants to say that OSM is a geographic database so the fact that the stop is on the west side of the intersection can be computed. But then the reductionist argument is that most stops name could also be computed if the name is the cross street. So I'm not opposed, but still think that "what's announced on the bus/streetcar" is a good guide (when you're on the vehicle, you'll hear/see the stop name=* being announced; when you're finding the stop on the street via app, you can usually see its location on a map in addition to seeing the name?). I think in some cases TTC does announce "west side" in the stop names, especially when it's got stops on both sides of a large suburban intersection.

I'm not aware of any apps using tags like official_name=* or description=* for user navigation. I do know OsmAnd does use OSM public transit data if you want to give it a try - as far I can tell it uses only the stop name=* and the route ref=* and name=*, so the description=* won't necessarily help you.

For updates, in my experience transit routes generally don't change that much once mapped in Toronto (streetcar construction detours notwithstanding). I think not all TTC routes are fully mapped with PTv2 relations, and getting that in would be a benefit. Then mapping the 905 transit systems - many of them are there, but incomplete, or not updated in ~8 years and there have been rearrangements. On programming side, creating a QA tool that compares information in GTFS feeds or on agency websites with what's in OSM and flags differences for review would be cool! I don't know how much of stuff like this has been done for OSM already.
