What is the main reason for the prohibition of operating a bus with interior lights on during daylight hours?

Operating a bus with interior lights on during daylight hours is primarily prohibited to avoid unnecessary battery drain. During daylight, natural light is typically sufficient for passengers to see inside the bus, making artificial lighting redundant. Using the interior lights unnecessarily can lead to additional power consumption, which can be particularly problematic if the bus's battery is not adequately charged or if the bus has to operate for extended periods without recharging capabilities. Therefore, minimizing the use of interior lights helps preserve battery life, ensuring that the vehicle can function effectively throughout its scheduled route.

While preventing overheating, enhancing driver visibility, and compliance with safety regulations may also be considerations, the key focus in this context is on the energy conservation aspect, making unnecessary battery drain the main reason for the prohibition.