What is the allowable leakage when checking the stoplight switch?

The allowable leakage when checking the stoplight switch is that there should be no leakage. This criterion is crucial because any leaks can indicate a failure in the system that may compromise the functionality of the stoplight switch, which is essential for indicating to other drivers when a bus is stopping. A properly functioning stoplight switch ensures safety by providing clear visual signals. Therefore, having no leakage demonstrates that the switch is in good working condition and capable of performing its intended function reliably.