jeff m:

Are the columns being hit by aisle travel? If so, should the loads be trailing? Are the columns being hit by spotting from the aisle? If so, are the columns obstructed by the load being spotted? How congested is your facility? Are aisle widths adequate?

I recommend you stop random forklift operations and get in the operator's seat to determine yourself the actual visibility? If it is a visibility problem, you will know what the operators may be up against trying to maintain production levels.

Without seeing your facility layout and the actual forklift movement, this is just a shot in the dark. If it were my problem, I would start by determining the visibility factor including if operators can see your safety markings from the operator's seat with varying loads.