There is in fact no highway that accesses Aguas Calientes from Cusco, so taking a bus for the whole journey is not really an option. The trains are your best wager! The simplest way to get to Machu Picchu is always to go ahead and take train to Aguas Calientes. https://doctorbookmark.com/story16939591/helping-the-others-realize-the-advantages-of-machu-picchu-tours