I would think that, on a shortcut, particularly in bad weather, travelling it would be a BAD idea-regardless of the advice of locals. It likely isnt travelled much, and if something were to happen, and you couldnt self-rescue, you may be stuck for some time-or die. Saving time isnt a reason to die, IMHO. I would MUCH rather be late to an appointment, and arrive safely, then shave 20 mins off a commute on a sparsely travelled road-again, in bad weather, the likelihood of others travelling it are small. At least on main roads, if something goes wrong, there is a decent possibility of another commuter coming by.
Of course, this is all assuming you are travelling by vehicle.