America's Marine Highway is a United States Department of Transportation (DOT) initiative, aimed to use the United States' 29,000 mi (47,000 km) of navigable waterways to alleviate traffic and wear to the nation's highways caused by tractor trailer traffic. In 2007 Congress included provisions to Public Law 110-140, to 'Offer a waterborne alternative to available land-side transportation services using documented Vessels' and 'Provide transportation services for passengers or freight (or both) that may reduce congestion on land-side infrastructure using documented vessels.' As the United States' population grows, its need to transport freight within its borders also grows. This increases the need for fossil fuels and damages the nation's highways. It is estimated that in 2008, 3.7 billion