Hairpin turn

Acute curve (often one of a series) in a road, especially on a steep incline

A hairpin turn is a bend in a road with a very acute inner angle, making it necessary for an oncoming vehicle to turn about 180° to continue on the road. It is named for its resemblance to a bent metal hairpin. Such turns in ramps and trails may be called switchbacks in American English, by analogy with switchback railways.

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