Cycling and traffic laws are a weird dynamic. Cyclists do have to obey the rules, but UNLIKE when driving a car, to the extend you obey them is MUCH more dependenent on conditions and time of day. To use Tone's example, if youre riding through a nice quiet neigborhood on your way home, a cyclist is NOT going to come to a full stop for every stop sign. That would be pointless. A good cyclist will come to an intersection like this, look both ways, determine that the road is clear and keep going. If there is a car there, s/he may slow down and yield or keep going, depending on the action of the car. Its actually the same with red lights. Youll come to a light, slow down, look both ways and if traffic permits, go through it and if traffic doesnt permit, stop. To illustrate this...I go down a VERY busy road on my morning rides. At 530AM on my way out when the road is very very quiet, I wont stop for lights or stopsigns...just as I approach, make sure traffic is clear and keep right on going. But on the way back at 830AM in the middle of rush hour, its a whole different ballgame and Im MUCH more in tune with the cars and stop lights and Im very careful to "follow the traffic signal rules" and what not.
I cant speak for the fools who ride on sidewalks, against traffic or just blow through lights without looking. Obviously, there is no place for that. But cyclist's rode rules are governed MUCH more by traffic conditions at the time and not as much by the rules automobiles are governed by.
One thing thats a peeve of mine...this notion by cars that I have to get to the shoulder. No....share the road. I dont see you driving your car in the shoulder, dodging roadkill, tree blowdown, dirt and garbage. Dont expect me ride my bike in that crap.