Source of Image: HHH, Inc. : http://www.hhhincorporated.com/stay-back-200-feet-sticker.html
Is this the legal doctrine of "Self-Proclaimed Immunity?" Ostensibly, it is an attempt to publicize the existence of an inherent danger that may not be obvious to the following vehicle. And it is probably to cumbersome for the sign to read "You have been warned that construction vehicle may spew stone and rock at any time regardless of the level of care or precaution that has been exercised by the construction crew and the driver of the vehicle. So, protect yourself by staying back more than half the length of a football field or take another route home." But I think that is what is meant. Thanks for the warning, but if you are negligent, you can't escape liability on the basis of "I told you so!"
Where is the outrage!