During World War II, Bomber Base was a bus line that ran on Franklin (the same street as the main part of the Gentilly streetcar line) from Gentilly Road to the lake front, then east to the airport, which was in use by the military.  Between Gentilly Road and Dreux, it overlapped the Gentilly car line.  In effect, it extended the car line so that workers could get to the military installations on the lake front.  Since the only transit lines that it connected to were the Gentilly streetcar (which ended at Franklin and Dreux) and the Gentilly-Broad bus (at Franklin and Gentilly), this simple transfer served the purpose.