Safety Glass. Glass shall be installed so that the identification mark is legible. Windshields. The windshield shall: Be large enough to permit the operator to see the highway clearly; Be slanted to reduce glare; and Be installed between front corner posts that are so designed and located as to afford a minimum of obstruction to the operator's view of the highway. Stirrup Steps. There may be at least one folding stirrup step or recessed foothold and suitably located handles on each side of the front of the body for easy accessibility for cleaning the windshield and lamps. Windows. Glass in passenger compartment side windows, doors, and rear windows shall be AS-2 or AS-3 laminated safety glass. Passenger compartment windows shall: Operate freely; Open 9—10-1/2 inches from the top only and provide an emergency exit of at least 9 inches by 22 inches; Have all exposed edges of glass banded; Be free of window guards or bars either on the inside or outside; and Be aluminum-framed split sash. Windshield Wipers. Automatic, variable, two speed or intermittent windshield wipers with nonglare arms and blades shall be installed so as to clean the maximum possible area of the windshield. The windshield wiper blades and arms shall: Be heavy-duty; and Be at least 14 inches long.