If you have to cross lanes of traffic, you have to wait for a light. If you are merely "changing lanes" you just have to wait for right of way. (in my state at

If you have to cross lanes of traffic, you have to wait for a light. If you are merely "changing lanes" you just have to wait for right of way. (in my state at least) you're allowed to turn left from a one way to a one way on red, because you're not crossing any other lanes. So do the math... how many lanes are involved. If it's just "current lane" and "target lane", you can go when the coast is clear. If there are ANY other lanes involved, wait for a light.