The airships used to cross the Atlantic in 24 to 36 hours, which is very fast for cargo movement. Very little cargo has to move at 500 miles an hour. The railway's average speed, by the way, is about 25 miles an hour. If you can go 80 miles an hour in an airship, that's actually quite fast and reliable. Crossing oceans is a very desirable market for them.
On the ice roads, my view is that a trend will continue until you see a change in the trend. We're seeing the trend continuing very dramatically, and it's not changing.
Mr. Ginter is the expert on ice roads, so I'll perhaps let him answer that question.