DETROIT:- Traffic jams cost US drivers an average of $1,200 a year in wasted fuel and time, and much more in Los Angeles, the city with the world’s biggest rush hour traffic delays, according to a study by INRIX Inc released on Monday. INRIX, based in Kirkland, Washington, aggregates and analyzes traffic data collected from vehicles and highway infrastructure. The company said the latest edition of its Global Traffic Scorecard report was based on 500 terabytes of data from 300 million sources.–