A backup to GPS, but really the precursor and consistently better system to GPS, is astral navigation.
In the USAF they affectionately referred to their NAS-14V2 system as a science-fiction icon.
Mounted behind the SR-71’s cockpit, this unit, affectionately known as “R2-D2,” computed navigational fixes using stars sighted through the lens in the top of the unit. These fixes were used to update the inertial navigation system and provided course guidance with an accuracy of at least 90 meters (300 feet).
I’ve driven with no running lights at night many times in rural and remote parts of the world.
I barely could see the driver’s hands rolling quickly back and forth on the steering wheel to keep us from driving off the cliff ledge to our left. He didn’t slow down after lights-out, and when I turned my head more towards him he said warmly l’appel du vide or something like that and smiled broadly at the barely visible road ahead.
Driving by astral navigation not only is feasible, it can reduce eye strain and increase safety.