Economist Charles Komanoff calculated that in New York City each additional vehicle that joins traffic during rush hour costs society approximately $150. This graph illustrates how flattening these travel peaks (similar to demand-response pricing and appliance controls that shave electricity loads) can produce city and even nationwide savings of congestion, time, pollution, and above all money. Komanoff has developed a pricing tool that dynamically assigns prices to the bridges, roads, and interstates that crisscross the greater Manhattan area, freeing up congested city streets and reducing emissions.
Felix, Salmon. 2010. “The Man Who Could Unsnarl Manhattan Traffic.” WIRED magazine. link