Riding in bike lanes is not
necessarily contrary to VC, though it may be. Please do not fall for the misinformation spread by those who do not understand VC and contend that VC advocates like myself are "VC extremists", and that part of our "dogma" is that "using bike lanes is somehow mutually exclusive with behaving as a 'vehicular cyclist' ". It is true that vehicular cyclists behave as if the bike lane stripe does not exist, and that many of us are opposed to bike lane stripes for various reasons (see
http://en.wikipedia.org/wiki/Bike_lane_debate), but that does not mean we do not ride in (and hence use) bike lanes. It means we treat the bike lane and the adjacent lane as one big wide lane, as if the stripe is not there, and choose the appropriate position within that lane for the given circumstances accordingly.
Diane correctly points out that VC is about choosing the proper lane for the given situation and circumstances, though vehicular cyclists typically do not view a "bike lane" as a separate demarcated lane (we ignore the stripe and ride as if it is not there). VC is also very much about choosing the proper position within a lane according to
speed positioning (between intersections) and
destination positioning (at intersections and their approaches). The speed and destination positioning rules of the road often guide the vehicular cyclist into riding in a bike lane (particularly between intersections, and at intersections and their approaches where the cyclist is turning right). Therefore, someone cycling in a bike lane may very well be adhering to the vehicular rules of the road, and hence may be a vehicular cyclist. It depends on the situation, factors and conditions at the time.
Your own question, "Is it illegal in California to VC when there are bike lanes?", is based on the assumption that VC and bike lane riding are mutually exclusive. Before we proceed, you must understand that they are not. If you still have any questions about that, please ask. Some people miscontrue "vehicular cycling" to simply mean "using the full lane". It isn't. You may want to refer to the Wikipedia entry on "vehicular cycling" for more information on this.
http://en.wikipedia.org/wiki/Vehicular_cycling
Now, perhaps you're asking, "is it illegal in CA to ride outside of bike lanes where there are bike lanes". The answer is NO, as long as you have a good reason. And the relevant law in CA, CA CVC 21208, has many exceptions in it for just about any situation a vehicular cyclist may need to leave the bike lane. You should read it, and study it carefully.
21208. (a) Whenever a bicycle lane has been established on a roadway pursuant to Section 21207, any person operating a bicycle upon the roadway at a speed less than the normal speed of traffic moving in the same direction at that time shall ride within the bicycle lane, except that the person may move out of the lane under any of the following situations:
(1) When overtaking and passing another bicycle, vehicle, or pedestrian within the lane or about to enter the lane if the overtaking and passing cannot be done safely within the lane.
(2) When preparing for a left turn at an intersection or into a private road or driveway.
(3) When reasonably necessary to leave the bicycle lane to avoid debris or other hazardous conditions.
(4) When approaching a place where a right turn is authorized.
(b) No person operating a bicycle shall leave a bicycle lane until the movement can be made with reasonable safety and then only after giving an appropriate signal in the manner provided in Chapter 6 (commencing with Section 22100) in the event that any vehicle may be affected by the movement.
http://www.dmv.ca.gov/pubs/vctop/d11/vc21208.htm
With respect to your original question, note subsection (4), which excepts you from having to stay in the bike lane
any time you are approaching a place where a right turn is authorized. Think about the significance of this every time you ride by a driveway, alley, mall entrace, or side street, not to mention any major intersection. What do you think is the purpose of putting this particular exception in the law?
As to your "I always feel guilty about being an inconvenience to cars" comment, please read (or reread) the opening post of my "attitude" thread,
http://www.bikeforums.net/showthread.php?t=106637, because I tried to address this very issue there. Bottom line, in order to act as a vehicular cyclist, you must believe,
deep down, that you have the same right to travel on the roads as does any other vehicle driver. You are not a second-class visitor on their territory, only allowed to use whatever they are not using. You have the
same right to use whatever part of the roadway you require to reach your destination reasonably and safely. And that often means leaving the bike lane. In fact, I prefer to think of it in terms of mostly riding in the bike lane, and riding that far right on the relatively rare occasions when it is safe and appropriate to do so.
If you study all of the exceptions in 21208 carefully, I think you will find that at least one of them applies most of the time you are cycling on the road. Often, the bike lane is simply too full of debris to safely ride in it. Or you might be going the same speed as traffic. If you're going the same speed as traffic, but down hill and pretty fast, riding in the bike lane is still not safe. If none of that is going on, most likely you're preparing for a left turn, about to pass someone or go around some other obstacle in the bike lane, or are approaching a place where a right turn is authorized. Only when none of that applies, is it safe and reasonable (not to mention legally required) to temporarily ride in the bike lane, and stay there only until one of those exception conditions becomes true again.
Serge