How about Long call reseve for everyone unable to hold any kind of line?

Two options come to mind:
-12 hr callout minimum before a trip showtime.
After assigned trip ends you will have a 10 to 12 hr period without being required to be phone available.

or

Continuous phone availability during scheduled work days, but with a 24 hr callout period minimum. (cannot call you with less than 24 hr from showtime)

The latter would be a huge relief to those that commute to reserve.