Each municipality which is now, or which hereafter may be, engaged in the operation of a municipal airport, whether within or without, or partly within and partly without the geographical limits of such municipality, shall have the same police powers over such airport or landing field as it now has, or may hereafter have, over territory within its geographical limits. Such municipality shall also have the same police powers over all portions of public highways beyond the geographical limits of such municipality, but within one quarter of a mile of such airport as it is now, or may hereafter be, authorized to exercise over public highways within its geographical limits.