The Trem do Vinho, often called the Maria Fumaça, is a tourist train rather than a normal way to get around. It runs between Bento Gonçalves, Garibaldi, and Carlos Barbosa with music, theatre, grape juice, and wine worked into the ride.
You come for the atmosphere more than the engineering. It is cheerful, a little staged, and useful if you want a soft introduction to the region's Italian immigration story before heading out to the wineries by road.