artery vs guardrail

artery

noun
  • A major transit corridor in a system of roads, rivers, or railway lines. 

  • Any of the muscular- and elastic-walled blood vessels forming part of the circulation system by which blood is conveyed away from the heart regardless of its oxygenation status; see pulmonary artery. 

  • Hyponyms: alloartery, arteriole, endartery, microartery; see also Thesaurus:artery 

guardrail

noun
  • A rail set alongside a dangerous place as a barrier, to improve safety. 

  • Any barrier designed to prevent accidents or mistakes. 

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