The method of transporting a pallet jack that is the main tool for the trucker to shuttle their freight within, possesses potential hazard . Not properly securing the pallet jack can cause damage to freight, trailer doors and the pallet jack itself. 

There have been cases where the trucker has sustained injury from the pallet jack falling on them upon opening the trailer or trucks doors. One common procedure of laying the pallet jack on it's side for in transit transport has yielded numerous back injuries from wrestling a 200 lb object into positions it was not intended for.

Attaching the pallet jack with tie-downs, bungee cords or load bars poses a time and motion problem as well a liability issues to whatever it is attached to.

The best and safest method is the use of a simple rubber Pallet Truck Stop.  In December of 2005 one of the trucking industries leading publications Heavy Duty Trucking deemed the Pallet Truck Stop as one of the trucking industry's Best 50 Products.

Some companies have tried marketing takoffs like using plastic stops (does not grip to the surface as well), wedges with magnets (the first pothole dislodges the pallet jack) and V shaped chocks and restraints (again can be easily displaced).

My suggestion is to seriously consider the rubber Pallet Jack Stop.