Shapes are equally crucial for swift comprehension:

• Octagon (8 sides): Exclusively for stop signs.
• Equilateral Triangle: Yield signs, signaling to slow down and give way.
• Pennant: On the left side of the road, denotes no-passing zones.
• Diamond: Indicates warnings, often at construction sites or for road changes like curves, dead-ends, or hidden intersections.
• Horizontal Rectangle: Provides guidance, e.g., “road closed” or “one-way.”