Turtle,
Are you saying it is all right?
Greg, of course it's all right.
Putting aside the fact that a truck has no expectation of privacy when it's parked out in the open in the middle of a truck stop parking lot, a commercial motor vehicle is by its very nature pretty much the opposite of a low profile vehicle, what with the DOT identifying numbers on the door, the carrier advertising on the box, and the fleet truck numbers on the sides. Such a vehicle cannot hide in plain sight. It's got "Look at me!" written all over it, especially that one in particular, with the eye-catching, double-take, less-than conventional sleeper, not to mention having the most recognizable logo in the world on its side.
That truck is a Kodak Moment on wheels.
Like I said, tho, if you don't want to be photographed, don't go out in public. A truck out in the public view, say, in a truck stop parking lot, there is no difference between standing there and looking at the truck, and in standing there and photographing the truck. You, me, and countless others are photographed daily, by security cameras, red light cameras, television news cameras, cell phone cameras, and, of course, by Phil.
Anything in public view is fair game to be photographed, with very, very few exceptions (mostly military bases). If you can be there, you can photograph there, and even if you can't be there, if you can still see there, you can photograph there. A photograph of a truck in public view poses no more of a security risk than the truck being in public view in the first place.