A certain Wodehouse character, a wannabe mystery writer, first used to think up titles that he decided were really cool for his novels, and then used to think up plots for the titles. "The Case Of The Whispering Windmill" or "The Mystery Of The Dyslexic Mummy", for instance. Road seems to have happened similarly. Tech-God Varma had this grand visual in his mind of a barren arid ad infinitum highway flanked by sand dunes and melting into mirages - the single image that Mad Max leaves in your head years after you've seen it - and decided to make a movie centered around that.