Taxi Driver didn't get it's start as a script only. Some crudely drawn storyboards accompanied the screenplay long before the film was ever green lit for production. Have a look at how a great motion picture began. “Storyboards express what I want to communicate,” Scorsese told Phaidon in 2011 for an article on the exhibition “Between Film and Art: Storyboards from Hitchcock to Spielberg.” “They show how I would imagine a scene and how it should move to the next.” via OC