I'm also interested to know what's the plan in case of a brutal rupture of the tunnel. A wall of air rushing through the pipe to meet a car traveling at superso

I'm also interested to know what's the plan in case of a brutal rupture of the tunnel. A wall of air rushing through the pipe to meet a car traveling at supersonic speed doesn't sound very pleasant. Maybe they just plan to make the pipe sturdy enough that it wouldn't be a practical concern?