Well I know that somewhere in the world, people build air tubes that would just suck you through it and you'll end up to the other end. You will be traveling so fast that a trip from LA to New York would take just two hours. But I'm not sure if that's actually going to be made into a real thing.
Plus trains could be replaced with trains that float with magnets. That would be cheaper and more efficient because you would use less energy to move it since you take out friction on the tracks. And using only little energy, you can get that kind of train to go really fast too. Unfortunately, you would have to use special magnets and dry ice to keep the magnets cool to achieve this and that would cost quite a bit.