A tight switchback is a road or trail that has a turn that's too tight for the front and rear wheel to take the same line.
A switchback is a road which goes up a steep hill in a series of sharp bends, or a sharp bend in a road.
Switchback roads can look like hair pins or ZigZag and have many twist and turns to them.
Basically switch back roads or trails are a zigzag road, trail, or section of railroad tracks for climbing a steep hill.
A switchback is a curve that completely reverses the direction of a road.
The switchback roads are typically used in steep topography where the ground slope between two control points is greater than the allowable grade of the road.
A switchback lengthens road to allow more gain in elevation while maintaining the allowable grade.
In the U.S., we call the mountainous roads "switchback" roads, with the individual turns called "hairpin" turns.
In contrast to monotonously straight desert highways, Lombard Street, in San Francisco, incorporates eight hairpin turns in one quarter-mile block, making it what locals call the “world's crookedest road”.
If you see a road on a map that is in a ZigZag fashion then it's a mountain road or switchback road that can be hard to navigate especially if you've never driven or ridden on the switch back roads.
You have to drive slower and be more cautious on a switchback road than you would on a straight or less curvy road.