It would honestly be nice if airports had 'phone booths' like I've seen in high tech companies. Think 1 person sized meeting rooms in larger spaces. One door on the pod opens, there's a seat and a small desk inside. Enough to make a mostly private phone call.

In a public setting there should also be things like a panic / duress button. A simple lock (that only local security can bypass). Maybe an internal phone line of some sort. Possibly a wired connection to the net DMZ.

I hesitate to add a timer, because _sometimes_ people have real travel troubles while at the airport and need an extended duration to take care of that. Such nuances might not fit within the context of E.G. a 20 min max timer.