A case of unclear road signs

As an example of my previous post on driving tips, I'll talk about a intersection I go through daily.

This intersection is big and crowded. The one way road I usually ride to reach this intersection has 3 lanes. Next to this road is a 2 lanes road that become a bridge when reaching the intersection. Next to it is another one way road with 2 lanes, going the opposite direction from the first road. Since the second road described above become a bridge when reaching the intersection, it's possible to do a U turn from the first road, going under the second road, to the third road. So there are 3 roads next to each other at one side of the intersection, out of 4 sides.

The roads position on the opposite side of the intersection mirrors the 3 roads position above.

The left and right side of the intersection (from the orientation when I reach this intersection) each has 2 one way roads, with 3 lanes each.

Now, the road I ride to reach this intersection has two traffic lights. The first one indicating the rule for going straight, the second one indicating the rule for turning right (turning right, not doing U turn). There is a police station under the bridge road from the opposite side of the intersection.

The big question is, can I do a U turn disregarding the traffic light? Consider some additional facts. Polices sometime exist in that station, sometime don't. When they exist, they always never look at the direction I come from. When they don't exist, sometime a few cars will do U turns when the light is read, sometime they don't. Consider also that the roads perpendicular to the road I come from, will be forced to use 2 lanes (instead of 3 lanes) if cars coming from the road I travel force a U turn, disregarding traffic light.

btw, I hope that bad grade I got from a course I insisted to take, really worth it.. since I took that class to improve my description skill..

Anyway, given the above conditions, is it allowed to do a U turn disregarding traffic light? It turns out that such U turn is allowed even though the intersection is crowded and the U turn will disrupt the path perpendicular to the road I travelled. Strange isn't it?