Why do most states require a hazmat placard to be visible from a distance on all four sides of certain loaded vehicles?

Pick an answer

1. Four-sided placarding only applies to loads crossing state lines
2. Placards are only required on the front of the vehicle, not all sides, which sounds right but isn't, at least for vehicles
3. It's purely a stylistic requirement with no safety function
4. So the hazard is identifiable from any direction someone approaches the vehicle, including emergency responders

Correct!

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