Well it varies around here. Most run a spreader of some sort with material in it, or the bed of the truck. So that pretty much takes care of the weight issue. I have a sub that runs just a truck, we weight him with a bucket of snow during the storm, and that does him fine.
If that doesnt work, try befriending a person or business with a fork lift, and have them load a 1/2 skid of your choice in the back, and when done, just return the material. Use blocks or bricks or something along those lines. Or use bagged salt on a skid, that way when you need it, its already there.
Dino