Load shift is when your load leaves the spot where it was originally placed and moves to somewhere else. Usually to one side of the trailer. It can also move to the front or back of the trailer. A shifting load can throw off your axle weight and it can also end up being the cause of your trailer flipping
In this situation that happened to me I didn't sweep the floor and the previous load was pellets of plastic. Then I later ended up driving the trailer axles through a mudhole in a parking lot. It was deeper than I expected but at the end of the day, it was still preventable.
These are other more common ways that loads could shift
It may be obvious but i will state it anyway. Some of the ways to avoid load shifting is too be observant of where you drive and avoid holes in the parking lot. Also...
My mistake first started by not sweeping the floor before getting loaded. I didn't really think about the fact that the pellets would make it easier for the pallets to slid. Even if it is heavy.
Recognizing your center of gravity helps you to know how easy or hard it will be for your load to flip over or shift.
If you have a high center of gravity and free space between the sides of the load, it is easier for the pallets to fall over. Even if the pallets at the end of the trailer have air bags, often they don't put the bags all the way up the trailer.
Unfortunately, there is usually no easy way to fix your shifted load. If you arrive at the dock with it, it can cost you in damaged claims. (For company drivers, it will cost the company) But it will also cost you in time for them to get the freight out of the trailer.
If you get stopped at the weigh station like I did in the photo, well....that's when it get's interesting and expensive.
Usually the weigh station DOT officer can point you to business cards left on the window sill or something. If that doesn't work for you, you can always google, "load transfering" or "load shifting" or something similar.
The bad thing is this service is not abundantly available. So try to avoid it from the beginning.