Port-a-Potty Mobile

I'm driving home and I'm stopped at this intersection and I see to my right the cars coming and among them is a truck with a flashing light on top, and I think, "Why the flashing light? Emergency? Construction?" And then, the car comes into view and it is pulling a "Texas Outhouse," and suddenly, the flashing light was oh so appropriate.
I mean, people should pull over. It's just not safe.