The US build the Interstate highway system from 1947 to 1964. This enabled cars and trucks to increase the distance traveled in a day by as much as two times to four times compared to 1920. It was a 1.2 to 1.5 times benefit compared to the roads of 1945. The gross domestic product (GDP) grew at an annual compounded rate of 3.9 percent from 1947-1964. The transport of freight in the U.S. grew considerably during this time. There was also the post-war economic boom as military production and investment was redirected to the domestic economy. However, President Eisenhower said the Interstate was the single biggest contributor.