guardrail vs roadway

guardrail

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

  • Any barrier designed to prevent accidents or mistakes. 

roadway

noun
  • The portion of a bridge or railway used by traffic. 

  • The main or central portion of a road, used by the vehicles. 

  • A way used as a road. 

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