This does make traveling through areas high above your level quite the challenge -- as I'm sure they were intended to be. Die, run back, rez a bit further down the road -- then simply wash, rinse, and repeat until you've reached your final destination. However, over at Mania's Arcana, Mania provides us with two tricks that will allow you to do the majority of your traveling as a ghost. The trick? If you die on one continent and then spirit rez in the other (yes, you can ride boats and zepplins as a ghost!), you'll be allowed to rez right where you want to. And, perhaps more conveniently, if you run as a ghost to wherever you wish, disconnect, reconnect, and then try to spirit rez, you'll be allowed to.
Now, both of these little tricks smack of overlooked bugs, as the intended behavior of the game client is clear. But at present it is a working strategy in-game that can be used to more quickly move you from point A to point B.