Road signs in Vietnam, what do they mean?

I was walking around the streets of Da Nang yesterday and encountered a few road signs. I am from USA so unless things have changed a lot since I was last there I don't think I am incorrect is stating that we don't have these signs there at all.

I took a guess at what they meant based on my surroundings but do you know what they mean?

I kind of presumed this meant that there was a 4 way intersection coming up. These signs are all over the place so I presume that is what it was for. The thing was that the sign was almost unnoticeable behind the plants whereas it was pretty evident that there was an intersection. Vietnamese intersections do not have stop signs in this town, it is a free for all that somehow ends up working.

This one is a bit more bizarre. Is there some sort of 70's robot up ahead? I think that this one is referring to a much smaller road that is joining the bigger one up ahead, a junction of sorts but not for the road you are on. This can't be terribly helpful to motorists though and it is probably a waste of steel and cement because the people on the major road are moving far too quickly for this sign to be of much use. If it is, in fact, referring to the junction that you can see in the picture above, the road itself would be far more noticeable than the sign. Maybe it is more helpful at night.

This is just what I am guessing. I have never seen signs exactly like this in any other country in the world. What do you think?