I lack the speed to keep up with traffic even leaving from a light ... any car can hit 30 mph in a few seconds and i cannot hit it at all except on a downhill. I take my place in line sometimes ... but I also don't like the feeling of sitting, flat-footed, while some driver pulls up and over me because s/he is looking at he car in front of me instead of me.
Intersections are always going to be issues because they are choke-points----unless there are bike lanes on both sides, cars will be coming both ways, leaving little room for them to swing wide around the cyclist who needs to occupy that bit of road. I'd rather make the cars wait .... but with some long intersections that would Really annoy drivers, and don't like having angry drivers behind me.
I guess the answer is steroids, EPO, and testosterone supplements.