From Family Handyman · Alex Shoemaker · · 40s
Diamond Signs on Trucks Matter
Truck diamond signs warn of dangerous cargo, empty ones mean no current hazard.
In brief
Truck diamond signs warn of dangerous cargo, empty ones mean no current hazard. Empty diamond-shaped placards on trucks indicate no hazardous materials are being transported at the moment. Originally reported by Family Handyman.
What Diamond-Shaped Signs Mean
Truck diamond signs identify hazardous materials being transported, with empty holders indicating no current hazard.
How Placards Work
Placards use colors and symbols to show flammable, corrosive, or toxic materials, with red often meaning flammable.
Why Holders Are Empty
Truck operators leave holders attached for future shipments, so empty holders don’t mean no hazardous materials.
Regulations for Placards
PHMSA requires placards on both sides and ends of vehicles, with rules against misleading signs.
Here's the gist
Empty diamond-shaped placards on trucks indicate no hazardous materials are being transported at the moment.
