Road Use per Mile We have in the last 115 years built road after road and we have buried many as each became too old, out of date safety wise, or too costly to maintain.  The average road in the U.S.A. last about 20 years before it needs to be recoated or upgraded at a cost of millions to billions.  To replace all our roads with new technology, surfacing, safety improvements, etc., will cost trillions.  {2016 estimate is a minimum of $3.8 trillion, with $5 to $7 trillion being more accepted by those that study the situation} At the same time our roads, bridges, and such are deteriorating, our supply of estimated oil is increasing.  The problem is that the number of vehicles worldwide is increasing and the cost of oil will be many times what it currently is as it takes more energy and technology to retrieve sufficient oil for the needs. "Some experts believe there could be 2.5 billion automobiles worldwide by 2050." REF: wonderopolis.org  This means that we will need much more oil {gasoline} than can be produced, and much of the oil will be assigned for use of our Military, thus cutting supply to the average traveler even more. {Our Navy is switching over to fuel made from mustard seeds and used cooking oils} This trend will be serious by 2050 and only get worse as the decades tick by.  High-Speed Rail that is powered by solar, wind, and other clean renewable energy sources will be needed for our infrastructure, our commerce, and our national security.   The BorderTransportationSystem would be the beginning of a two continent, multi-nation infrastructure that would bring resources and jobs to millions. Index of ... History of the US Highway System Number of U.S. Aircraft, Vehicles, Vessels, and Other Conveyances World Energy Technology Outlook – WETO H2