created a national network of interstate highways to serve the needs of commerce and defense, as well as the convenience of citizens. The construction figured as the largest federal construction of US history (47,000 miles, and contains 55,512 bridges and 14,800 interchanges). Using gasoline taxes, the project took two decades and a half to be completed. This project transformed American society, giving American liberty to move using their own cars (the automobile industry was also boosted because of this project), instead of a passenger railroad system.