After Ike's inauguration, Harry returned to the White House, picked up his luggage, hailed a cab for he and Bess and proceeded to Union Station. He and his wife made their way through the crowded terminal, then stood on the platform waiting to board the train back to Independence.
They were unaccompanied throughout.
http://archives.chicagotribune.com/1977/05/08/page/6/article/display-ad-555-no-title