This is the documentation of version 1.0.0-rc.4. Go to the latest version, 1.0.0-rc.5.

Function isHairpin

isHairpin(
    curve: Pick<
        CurveSectionProps,
        "headingChangeInDegrees"
        | "radiusInMeters"
        | "maneuver",
    >,
): boolean
Whether a curve is a hairpin: a bend of the road turning 140° or more on a radius of 40 m or less, as the numbered bends of a mountain pass do.
Parameters
- curve: Pick<
      CurveSectionProps,
      "headingChangeInDegrees"
      | "radiusInMeters"
      | "maneuver",
  >
Returns boolean
Remarks
- A wider bend that turns as far, as where a valley road swings round a spur, is a horseshoe a driver takes at speed, and no hairpin.
- A curve at a maneuver, as a roundabout or a turn at a junction, is no hairpin however far it turns.
- A curvy stretch's hairpinCount counts its curves this says yes to.
Example
```
const hairpins = route.properties.sections.curve?.filter(isHairpin) ?? [];
```