Is it generally the case that bikes are allowed to use the "full lane"? Many blogs and other sources of information on cycling advocate "riding like a car" or "taking the lane" as a way to increase safety and visibility when riding on a road. But such advice presupposes that doing so is legal.

Is it generally the case that bikes may use the "full lane", or is it better to check with local ordinances? Is there a general rule of thumb one should apply in cases where one is not certain about local rules?
For any question about law, you always have to check local laws.

The general rule is that you go with traffic and ride as far to the side as safe, taking the lane when it makes you safer. In many places this is how the law is written, but even when it isn't you may wish to do so.

From what I recall of the League of American Bicyclists safe cycling class I took, in the United States you're allowed to "take the lane" basically anytime that doing so is safer.  The exact laws vary from state to state, but they all basically allow this same behavior.

Reasons to move away from the side include:


hazards (glass, gravel, bad pavement, possibly opening car doors)
the lane isn't wide enough for a car to pass safely (to discourage dangerously close passing)
where a right turn is possible (to avoid right hook hazard)


Whether or not you're required to use a shoulder or not is different in different states. In California you're allowed to use a shoulder, but not required to; a narrow lane and wide shoulder allows you to legally use the full lane (but riding on the shoulder might be better).

Police often don't know the proper rules for bikes and mistakenly think you're always required to ride as far to the right as possible. Other road users often have that same problem.

The key phrase to look for to learn more is "vehicular cycling". There was a big move to vehicular cycling in the 60s and 70s, an I've noticed many laws that make it explicitly legal date to the 70s.