[hat_man]

My worries would be massive deceleration caused by blockage or tunnel displacement. Earthquakes can do some funny things. I have visions of that experiment years ago with the guy sitting on the front of the modified rail car testing the effects of, what was it acceleration of deceleration, on the human body.

That and in the event of a power failure wouldn't the mag-lev system fail causing all pods to "coast" to a stop? A pod with a light passenger would stop sooner than one with a heavier passenger, right? Would friction from the heavier weight be enough to overcome the momentum the heavier weight would create being propelled at such a high speed? That would be the heck of a rear end collision.