[Practicality]

For what it's worth, I was taught to sit in the intersection when making a left turn in driver's ed.

Maybe it's an east west thing, but here is a video of a guy complaining about people who DON'T enter the intersection: https://www.youtube.com/watch?v=q_bcjCOzob4

Again, he is saying that the proper thing to do is to enter the intersection and sit, regardless.

So, it seems like the issue may be that in some areas this behavior is promoted (even in drivers ed classes) and in others it's illegal.

Of course, I am not from a large city that deals with gridlock, so that may be part of the difference.

[sanderjd]

If there is no space in the lane you're driving into, whether turning or going straight, you should not enter the intersection. That video just doesn't deal with the case of the lane you're turning into being full already.

[rconti]

You're supposed to enter the intersection to make a restricted turn across oncoming traffic. Though I believe only one car should do it at a time.

It's different from gridlock because you know that when the oncoming traffic stops, there is somewhere for your car to go.

[ensignavenger]

Except that you block the view for oncoming vehicles turning the opposite direction (their left). A properly labeled intersection has white lines (in the US, other places may use something else) that indicate where to stop, and if engineered properly, stopping before these white lines leaves a clear view.

[dsfyu404ed]

which doesn't matter because after the oncoming traffic gets the red light you take your left and are no longer blocking anyone's view.

[ensignavenger]

Huh? You are still blocking the view and preventing the other side from turning left safely until the traffic clears and you can turn.

[furyofantares]

It annoys me as well when people don't enter the intersection on green when waiting for oncoming traffic to clear so that they can turn left. However I don't think it's related to the gridlock discussion unless the road you are turning onto is backed all the way up to the intersection, so that you will not be able to complete the turn even when oncoming traffic clears. In that case I believe you should not enter the intersection.

[amalag]

Your comment is not about gridlock.

[serge2k]

You are supposed to enter the intersection when turning left (then turn when safe), but not if there is no room to complete your turn in the target lane.

The whole point is to not have people clogging the intersection and preventing movement when the lights change. That's what creates gridlock instead of just a backup on one street.