Yes, interstate signs in the United States are pennant-shaped, specifically for warning signs indicating a no-passing zone. However, the standard interstate highway markers themselves are not pennant-shaped; they are typically shield-shaped with a distinctive design that features a blue and red color scheme. The shield shape is designed for easy recognition and visibility for drivers on the road.
pennant
Interstate highways are identified on signs with a shield-shaped design. This distinctive shield shape makes it easy for drivers to recognize and navigate interstate highways across the United States.
Ohio is the U.S state with a pennant-shaped flag
Signs which denote Interstate Highways are red, white, and blue.
The flag of Nepal is shaped like two triangles, one above the other like a cavalry pennant.
C
means no passing zone
I'd say the one that looks like a triangle.
Yes, stop signs are octagonal in shape.
Interstate highway
The Interstate 19 in Arizona is the only road in the US that features metric road signs.
Shaped like an X