Where should standing passengers NOT be allowed to stand on a bus?

STANDEE LINE: A line marked on the floor (or a sign) behind the driver's seat. RULE: On buses designed to allow standing, passengers must NOT stand forward of (in front of) the standee line. WHY: Standing in front of the line would interfere with the driver's operation, block the driver's view, and is unsafe in a sudden stop; the line ensures standing passengers stay back from the driver and front area; INSPECTION/OPERATION: The driver must ensure no passengers or carry-on baggage block the aisle or stand forward of the standee line before moving; PASSENGER SAFETY: Carry-on baggage must be secured so it doesn't block aisles or exits and can't fall on passengers; the driver is responsible for passenger safety, including managing where passengers stand and ensuring aisles and exits remain clear; the standee line is a specific passenger-vehicle concept tested on the endorsement — passengers must remain behind it for safety and to avoid interfering with the driver.