bollard vs refuge island

bollard

noun
  • A similar post preventing vehicle access to a pedestrian area, to delineate traffic lanes, or used for security purposes. 

  • A strong vertical post of timber or iron, fixed to the ground and/or on the deck of a ship, to which the ship's mooring lines etc are secured. 

refuge island

noun
  • A raised platform or other protective barrier in the middle of a street crossing, allowing pedestrians to pause safely in the middle of the road. 

How often have the words bollard and refuge island occurred in a corpus of books? (source: Google Ngram Viewer )