'I'm walking here!' A new model maps foot traffic in New York

Early in the 1969 film "Midnight Cowboy," Dustin Hoffman, playing the character of Ratso Rizzo, crosses a Manhattan street and angrily bangs on the hood of an encroaching taxi. Hoffman's line, "I'm walking here!" has since been repeated by thousands of New Yorkers. Where cars and people mix, tensions rise.