Most major cities are now using 5 modes: subway, mixed traffic bus, commuter rail, LRT and BRT. Each mode has a specific role to play. Toronto is essentially operating with 3: subway, bus/streetcar in mixed traffic, and commuter rail.
Toronto, at this time, is relatively unusual in not having substantial BRT or LRT routes. It does have a couple of short BRT routes, but has not provided any broad areas where buses run out of traffic for long distances, the same can be said for light rail.
While Toronto does have Streetcars in the core, and a couple of sort of LRTs in, St Clair and Spadina, these do not have the level of signal priority, or the space to really qualify as full LRT. Toronto also lacks any substantial examples of BRT as dedicated roadways. Where the buses are completely separate from traffic in a line haul type operation. There have been past proposals for these in a couple of power corridors, and one is in place to serve York University.
So the question is what has made Toronto special, and why do we have such battles around modes, instead of service. Toronto had 2 critical experiences that changed how transit was approached in the city. The first one was the Scarborough RT, and the second a massive service reduction in the early 1990s.
The Scarborough RT was originally proposed as an early LRT. Streetcars operating in a closed right of way had been proposed (and why old Toronto Streetcars are unusual in that they actually have 100 km/h top speeds), when the province stepped in and proposed a new technology they wanted to develop. The province wanted to mix industrial development with transit and make Ontario a leading light in transit manufacturing. Thus came the Scarborough RT, a technology that has been adopted elsewhere, notably London for the Dockland Railways, and Vancouver as their Skytrain. However, the province never bought enough cars, left enough flexibility to allow new cars to be used (tiny tunnel at Kennedy), or went far enough with what was an excessively expensive technology for the application. Toronto, has since been stuck operating this line, which it cannot reasonably expand, or buy new cars for.
Toronto also went through a rather nasty recession in the early 1990s, where ridership imploded and the TTC drastically cut all transit services but subway. Subway however, continued relatively untouched, and became the gold standard service, because all other services were not well supported.
Further there was still a major push underway to extend rapid transit, and the alternative of LRT was still seen as new. They were easy to confuse with streetcars, and the mayor of the day was firm, “real cities have subway”, no repeats early of adoption of a new technology. Sheppard was thus built with a technology that was greatly outmatched the demand. However, just as importantly, built to attract new riders and development, not increase system capacity (which only a few years earlier had been seen as critical).
Another aspect of the TTC experience that needs to be kept in mind when their advice is being considered, is that while Toronto led for a period in signal controls, and was good with signal priority for Transit, this has not continued, and the TTC is actively aware of not being able to count on signal priority in areas where it is supposed to have it. This has been reflected in the St Clair schedule changes due to a lack of signal priority maintenance, and the signals on Queens Quay line when the cars returned, which have certainly not favored the Streetcar. This is allowed despite, the very high level of density and development.
The TTC needs to look beyond the city for best practice, and get serious support from the other branches that are involved. Traffic management, enforcement and by-law enforcement are critical, to the management of transit in the city. It is important to realize, the city traffic department has nearly as much to do with how surface transit runs in the city as the TTC. It needs to have transit be a priority over general traffic and should also be looked to for support of good service. The other important groups are the enforcement people, both bylaw and Toronto Police Services. Transit Priority needs to be real, maintained and supportive of smooth flowing transit, and left turn and parking restrictions need to be seriously enforced and intersection blocking needs to be an absolute non-starter for motorists or even pedestrians.