The Hollywood Reporter says that the Emmy Award-winning host will produce and star in the upcoming film, which is based on Rachel Simon's book of the same name. "Riding the Bus" — adapted for the screen by Joyce Eliason — concerns the relationship between college professor Simon and her mentally retarded sister. O'Donnell would play the handicapped sister Beth, a woman who spends her days riding the city buses of Pennsylvania.

Larry Sanitsky, who will co-produce the movie, told the industry paper, "It's kind of like a female 'Rain Man.' I think it's a very touching story which says a lot about sisterly relationships and what it's like as an adult and a child to have a developmentally disabled sibling in your family." O'Donnell, who optioned the original book in 2002, wrote this for the cover of the tome: "This is an amazing book, a beautiful story of the ties that bind. Two sisters, as different as they come, find the magic in each other's lives. This book touched my soul."

Rosie O'Donnell has appeared on Broadway in Grease! and Seussical and produced the aforementioned Taboo. She is also at work on a new autobiographical theatre project — Find Me — with Cyndi Lauper and director Richard Jay-Alexander.