This has probably been talked about before. But I've been doing a lot of research in regards to perspective and I'm kind of confused as to what to do when something is not parallel to the horizon line.

Take for instance this picture. The truck and trailer, as well as most of the concrete barriers would fall onto the same two perspective lines if you were to draw it out. But you see that one concrete barrier is cockeyed a bit. And would not fall on the same two vanishing points. Would the points then be moved for things that aren't parallel in order to draw it properly in perspective?

How would you measure it out so it matches the other barriers? Or would you simply draw it as if it was in the same vanishing point line and simply rotate it from that point to where it is resting right now?