 Drivers in New York City lost the most time to traffic congestion in the U.S., an average of just over 100 hours last year. Chicago ranked second at 96 hours and Los Angeles third at 89 hours, according to transportation data company Inrix. New York City tops the list of most congested cities in the world, followed by Mexico City and London. Inrix also finds 10 a.m. to 4 p.m. are the hours when congestion is heaviest.