You may want to consider a device that senses people or objects in-behind the truck so that when the forklift is in reverse, which hampers many operators views, or they simply don't bother looking backwards, it detcts and warns the operators of such obstructions. That would resolve the issue of loads, etc., in the front of the truck, which is not an issue because of the requirement to drive in reverse with tall loads blocking the operators' view. Otherwise, without being blind or careless, the operator DOES have a clear view of what's in front.

Whether it would be effective or not is yet to be determined.