These are relatively silly, non-negotiable "rules" found only in Toronto that local transportation advocates and planners feel have come from on high and cannot be transgressed. I'll start:
#1: Thou shalt not build one way streets. It has been decreed that it is bad for pedestrian vibrancy.
This is not a silly rule, in my opinion. It depends on what you want the streets to do. Currently, Richmond and Adelaide function well as off-ramps for the DVP, and their importance will likely increase if the Gardiner is brought down between Jarvis and the Don River.
However, as commercially viable, pedestrian friendly environments, they're dead. And the same is basically true of most one-way streets that I've seen: they become pedestrian unfriendly environments, and the value of businesses along the route decreases. Kitchener used to have complementary one-way streets around its downtown with Charles and Duke, and these streets were never ones for good pedestrian growth. In the end, council spent close to a million dollars restoring two-way operation on these streets. The downtown did not come grinding to a halt. Pedestrian use increased on these streets, and we're seeing a mild commercial upswing on parts of both.
I question the usefulness of one-way operation for Richmond and Adelaide west of Simcoe. Most of the commuters on the DVP don't appear to be heading to work here. It's here where the streets have some small-scale commercial life still in them. Richmond and Adelaide can remain one-way from Simcoe east to the DVP; the way the downtown functions, this operation will have no serious effect on how the street works for pedestrians. West of Simcoe, however, Richmond and Adelaide could use an infusion of pedestrian-friendly aesthetic, and one way to do that is to restore two-way operation through to Bathurst.
#2: Thou shalt not position a ROW anywhere but in the median of a roadway.
This is changing. When construction on the new streetcar tracks down Cherry Street takes place (between now and 2012), it will be along the east side of the roadway. I also suspect that when the Eglinton LRT gets built, the surface portion between the Brentcliffe tunnel entrance and Don Mills will be on an off-road right-of-way to the south of Eglinton Avenue (no intersections to contend with here). But for the most part, centre-of-the-median operation makes sense where it has been applied. If you have a lot of street crossings at grade, having an LRT right-of-way at the edge of a street rather than the middle severely complicates right turns.
#3: Thou shalt not use articulated buses
There are plenty of routes the TTC would love to use articulated buses on: 53 Steeles East, 39 Finch East, probably 29 Dufferin as well. And the TTC would be happy to use these vehicles, if they could get a normal 18 year service life out of them. We have yet to find an articulated vehicle that can reach that life-span without extensive maintenance. The standard 40-foot buses are thus more cost-effective over the long term. But technology is improving. Once a builder fixes the maintenance problems associated with articulated operation, the TTC will jump in.
#4: Thou shalt not build rapid transit lines that deviate in alignment from the arterial road. No diagonal alignments or use of existing railway corridors will be allowed.
Continue accordingly...
The City of Toronto contemplated this as early as 1909, and ditched it. Tunnelling under buildings is severely expensive. Even the 1909 diagonal-subway proposal relied on new diagonal arterial roads cutting through the downtown core. If we have to build these things, it makes sense to put them where it's easier to build them, and that's under streets, or on corridor rights of way.
Though I admit, it's fun to fantasize about what the city could have been like if the Spadina subway had taken off and gone directly northwest from St. George station, with stops at St. Clair/Bathurst, Dufferin/Eglinton (intriguingly possible thanks to Vaughan Blvd), Keele/Lawrence and Wilson/Jane.
...James