To determine what was considered a joke by the bus drivers, you would need to refer to the specific text or context in which this information is mentioned. Look for any statements or descriptions within the text that indicate something being perceived as funny or humorous by the bus drivers. Pay attention to any clues or key words that might indicate a joke or humorous situation. Once you have found the relevant information, you can provide further details or insights regarding what was considered a joke by the bus drivers.
