Which statements correctly describe standard hazardous-material placards on a placarded vehicle?
Correct answer: D – All of these statements
A placarded vehicle generally displays placards on the front, rear, and both sides so they are visible from four directions. Standard placards are square-on-point, creating a diamond shape. Federal specifications require each side to measure at least 250 mm, or 9.84 inches. Placards must also meet the applicable design, color, durability, and display requirements.
Source: Ohio Commercial Driver License Manual — § 2.23.3, “Lists of Regulated Products—Placards”, 49 CFR § 172.504(a) – General Placarding Requirements, 49 CFR § 172.519 – General Specifications for Placards


