If the intersection has dashed lane lines both approaching and leaving the intersection in your direction of travel then it is legal to change lanes in and near the intersection. Any solid lane lines and it's game off.

intersection

 

That brings up a good point of discussioin. Cross the dashed lines at a left arrow with multiple lanes? I thought the dashed lines were place holders. Quite a few times on left arrows, the inside lane car went right into my lane and damned near ran me over.

 

Usually turn lanes have solid lines where you approach the intersection, therefore no changing lanes. That one pisses me off. People always take the inside lane, even if they want the opposite side of the road after the turn, and by the time they're through the intersection they're all the way to the curb on the other side, whether you're there or not. Ignorant assholes.

 

One thing regarding solid/dashed lines. I was told by an officer a few months back that, if you'll notice there are 2 different widths of solid line. One is 6" wide - this is a RECOMMENDED no-cross zone. One is 12" wide (such as gore-zones on the freeway ramps) - this is BY LAW a no-cross zone.