Already running is a 97 Yonge bus that runs from Queen's Quay to Steeles, stopping at local streets along the way, and branches that short turn at key bus terminals on the Yonge Line. This really helps the long distances between a lot of the stations. Obviously, this is less frequent than the subway so it's just for local service. And there's night service
When Line 5 opens in 2022, there will be a 34 EGLINTON "local" bus running from Mt. Dennis Station to Science Centre Station. I'm assuming that is in case if an elevator is out-of-service at any one or more stations, the "route" will still be "accessible". In addition, should there be a service delay, passengers will still be able to use some transit along the route.
Shouldn't they have a "local" bus running along Yonge Street (Queens Quay to Steeles) and Bloor & Danforth (Kipling Station to Sheppard & McCowan Station)? Just in case an elevator is out-of-service or, worse, a "service delay"?
They could add (articulated) buses, if they need more.
Too bad they removed the streetcars on those routes, then they'll have a larger capacity vehicle at the ready.
For the University Side, there is simply no direct route along the west leg. And any local service for just this subway won't make sense. Just take parallel routes.
There is no daytime local bus service on Line 2, just night routes. Fair reasoning being that 90% of the stations are actually walkable to any place on the Bloor-Danforth Corridor. And ridership would probably be very low. Just take the subway.
Line 3 has the 43B and 903. 43B runs on Kennedy and Progress to Scarborough Centre (less frequent obviously). The 903 running on Brimley and Eglinton surprisingly is the only express route directly for providing extra service along the corridor between Kennedy and Scarborough Centre.
Line 4 has the usual 85 Sheppard East running on the street serving local streets from Yonge to Don Mills and further east with local and express service.