I always put extra space between me and anyone hauling things.

I once had to dodge patio furniture boxes on a highway because someone didn't strap everything down correctly. Didn't even realize they were shedding their cargo, it took several miles for people to get them to stop.

I always let these trucks get way ahead, or I speed ahead if they're going a little slower. I've actually seen one tip over, granted that was on a mountain road meant for passenger vehicles only, but still, I was close enough to be thankful we used a rest stop. Scary shit when you could actually get hit by a giant trunk.