[steve86]

But your odds are much better if you stay with the car.

Yes, the only time I might try to hike out is if I could clearly hear the sound of vehicles on a highway (not an aircraft, which might pass once and never return). Even with a nearby highway in this northwest terrain, odds are high you would come to a steep section or a stream and have to turn back. These people were in a remote area and the father should definitely have stayed in the car.

[AmeriBrit]

Those circumstances are where an English Bobby's Police Whistle would come in handy. We have one in the survival kits in all our vehicles.