Carferries come in assorted shapes and sizes. Most Great Lakes ferries were similar to the C&O and Ann Arbor boats, but the Detroit River and St. Clair River boats were originally open-deck and self-propelled before they were converted to tug and barge operations.
The "Incan Superior" on Lake Superior was an open-deck boat with a conventional bridge and superstructure forward of the tracks on the main deck. I don't think it was meant to operate year-round.
There were carferries between Florida and Cuba prior to 1960 which were enclosed but had an appearance and design different from the Lake boats.