Traffic congestion seems to worsen each year. This raises the question, how much does roadway congestion cost the United States annually. The Federal Highway Administration’s Highway Performance Monitoring System conducts an analysis to produce an Estimate of the total cost. Drivers in the 99 cost congested areas in the United States were sampled and for each driver the congestion cost in time and gasoline was recorded. The total number of drivers in these 99 areas was 171,000,000. Estimate with 95% confidence the total cost of congestion in the 99 areas.