Trains beat individual cars efficiency wise, largely because they are long and have low frontal areas, hence air resistance, for their size and carrying capacity. Get rid of the air, and why not go whole hog with lightning fast cars?
Heck, put in place mechanisms to charge e-cars' batteries when in tunnel, and you can not only shoot someone to Europe in an hour, but allow him to drive out of the airlock and to his final destination pretty much interruption free as well. With Elon Musk being the latest hawker of vacuum tunnel hype, maybe we'll finally get to see a Tesla with no need to apologize for limited range.....
More realistically, before even contemplating doing a passenger version, someone should at least do a preliminary, by soundly and reliably beating FedEx Overnight Air between New York and LA/SF. Then plan on going from there with acquired learnings.