function getStreetFeatures(OSM_data) {
  let street_features = [];

  for (let i = 0; i < OSM_data.features.length; ++i) {
    let feature = OSM_data.features[i];

    if (feature.geometry.type === "LineString" && feature.properties.highway) {
      let street_feature = feature;

      street_features.push(street_feature);
    }
  }

  return street_features;
}
Get all streets from the GeoJSON data.
@private

@param {Object} OSM_data - A GeoJSON Feature Collection object containing the OSM streets inside the bounding box.
@returns {Array<Feature>} -  array of street features.