Being in Control of the Intersection
Vehicles that legally enter a signalized intersection have the right to be there until they can safely clear the intersection. This is commonly referred to as being "in control of the intersection." This means if you are making a left turn at an intersection that has a solid green light for the turn lane and you are in the intersection before the light turns red, you are still required to yield to approaching vehicles, but you are allowed to make the turn in safety after the light turns red. You do not have to be out of the intersection before the light turns red.
Many accidents have been caused by drivers thinking they have to move quickly and they turn in front of oncoming vehicles. If you find yourself in this situation just wait patiently for the approaching vehicles to stop for their red signal and then make your turn. If you are stopped at an intersection and there is a vehicle in the left turn area, which entered under a green light, they have the right of way so you must wait for them to clear before moving forward.
Be patient, drive carefully, and always wear your seatbelt.