I'm astonished at how ignorant otherwise intelligent bicyclists often are of the rule common in most US states that they can and should take the traffic lane (and should take the center of the lane to block cars from edging around to their left) when they are stopped at a red light where there is a shared right turn/bike lane.

I often see bikers who have helmets, lights, visibility vests, etc., all signs of being clear thinking riders, parking themselves squat in the middle of the shared turn lane at a red, when they should be in the main stream of traffic for the duration of the wait (in fact the recommendation is to ride with traffic if your speed matches it, absent bike lanes).

When the light turns green, cars are stationary, and bikes accelerate plenty fast in the first few seconds. One or two turns of the pedal gets you over back into the right side, and onward into the continuing bike lane as you cross the street. This can happen in a couple of seconds without significantly slowing down any cars (unless it's a Tesla P85D, maybe).

Joining the main stream of traffic in front of a car at a red light (assuming you beat that car to the red) may miff some ignorant drivers (ignorance all around, right?) but they'll be pleasantly surprised that you are out of their way in no time when the light turns green. Obviously this doesn't apply if you're a super slow rider... in which case, people just need to be patient for a few seconds. The point is, if you are blocking a shared right turn lane, you are doing it wrong.