The shirts are part of the Disney Attraction Poster T-shirt series, and these were designed by Richard Terpstra in collaboration with Disney Design Group artists.
The original attraction posters were designed by Jim Michaelson, Erni Prinzhorm, and Rudy Lord back in 1977, according to The Poster Art of the Disney Parks – a book by Walt Disney Imagineers Vanessa Hunt and Danny Handke.
Railroad fans can purchase the special, limited edition T-shirts on the Disney Parks online store from January 27 until February 2. All orders will be shipped in six to eight weeks.
The railroad poster artwork (along with other attractions) will also be appearing on plates and drinkware items at Centerpiece in the Marketplace Co Op in Downtown Disney later this year.