[friendzis]

In my country there is very specific provision along the lines "it is illegal to enter intersection if an obstacle would force a stop in intersection and block traffic" which means that in a "turn left or go straight" lane you enter intersection and cannot turn left due to traffic and block traffic for cars going straight making that technically illegal. Human drivers, of course, do this all the time.

[usrusr]

Are you sure that moving, oncoming traffic is seen as an obstacle under that definition?

The real trick against gridlock is to equate the switch to green not as "go", but as "go, once the previous wave has cleared the intersection". The "don't enter before there is room for your car on the far side" is only an optimization on top of that.

[friendzis]

I am not a lawyer so I may not be 100% correct. As far as I remember my driving classes and other resources (cannot quickly find exact provision), anything that is not part of road infrastructure (there are intentional obstacles to guide traffic) and causes vehicle to change speed/direction is an obstacle, so moving traffic kind of is. I understand that this particular provision is specifically there to prevent gridlocks and is never enforced in this particular situation.

The way traffic works is somewhat dependent on region. I can go to another city an hour away and already feel a bit alien traffic wise there. This is relevant in discussion on autonomous vehicles: in any foreseeable future we need them to coexist with human drivers and abide by unwritten "everyone drives like that here" rules.

[xeromal]

If you come to LA, you'll see there's no way to avoid it. The majority of lights are unprotected left turn lanes. The cops here even break the laws and no one judges. Sure, everyone could make 3 right turns instead, but I'd imagine if everyone did that the damage from wasted fuel, smog, and extra traffic would outweigh the few accidents that happen due to cheating the left turns.

[ghusbands]

In situations in which my country has that same provision, it does not treat moving traffic that crosses your path as an "obstacle", so if you're turning across traffic, you're allowed to enter the intersection and wait there. It might be worth double-checking whether your country has a similar subtlety.