I would like to know if it is acceptable for a cyclist approaching a crowded intersection while the light is red and move to the right front corner of the lead vehicle in the left turn lane. This move would be made slowly while all vehicles are not moving and there is enough room in my opinion to reach the front of the line and signal my intensions from a stop position before the advance green comes up. When the advance green is shown I would make a wide left turn and signal my intension to move into the right curb lane when I am half way into my turn.

That would be lane-splitting, which I'm told is illegal in Ontario. I haven't been able to find an HTA section prohibiting it; maybe "fail to drive within marked lane"?

When traffic is heavy but there are no cyclists behind me, I will go straight to the other side of the intersection (on the right edge of the roadway) and spin around 90 degrees to make a "left turn" on the spot.

Hi Squishy, lane splitting would suggest that I am riding a motorcycle. I think that a bicycle and another motorized vehicle like a car in the same lane would be lane sharing. Isn't that what cyclist and motorists are supposed to do is share the lane whenever it is safe to do so?

A cyclist is riding a bicycle, which is a vehicle. A vehicle can occupy a complete lane by itself.

A vehicle can occupy the entire lane (i.e., position as to prevent others from passing within that lane), but is there a law prohibiting two vehicles from occupying a single lane, side-by-side, if both vehicles are "consenting" (not staring daggers or hand gestures) and the lane is wide enough? I have seen signs put up advising not to drive side-by-side on certain wide stretches of road, but I think those were all yellow cautionary signs, not white.