What is the minimum height for the letters "School Bus" on a school bus?

The minimum height for the letters "School Bus" on a school bus is 8 inches. This requirement is established to ensure clear visibility and legibility for other drivers, particularly in scenarios where a school bus is stopped, which is critical for the safety of children boarding or disembarking from the bus. Adequate letter size enhances recognition from a distance, allowing motorists to adhere to the appropriate laws concerning stopped school buses, such as halting when the bus has its lights flashing. Compliance with this standard ultimately contributes to safer road conditions in school zones.