Try an experiment: fashion a visor/shade type of arrangement out of stiff paper (file folder or something like that. Make it three sides of a square, then make another one so you have a pair. Push one onto each fog lamp so it blocks light from travelling up, left or right directly from the lens face. Try adjusting your visors so they protrude forward about 3 inches from the lens face. With the truck in the same position, turn the lights on again and see what changes in terms of wall/ceiling illumination. Maybe take another pic.
EDIT: I just saw the frontal pic of the truck. We usually talk about upward stray light, but there's a striking amount of downward stray light in this pic. Those streaks and splashes on the ground directly in front of the truck? That's stray light. No way can it possibly help you see anything -- if you want to put a good scare on yourself, speaking of experiments, try this one
with your own truck -- all that light can do is bounce off the ground and make trouble of itself. It's not going to cause as much backscatter/veiling glare as you might think, because light travelling at 60°-90° upward angles won't refract back to your eyes very strongly. But it will cause some backscatter, because the uneven surface of any pavement will send light rays headed in a large variety of angular directions, and with all that unusable light flying around, a proportion of it is going to wind up going bad places.