hauler vs tractor trailer

hauler

noun
  • A person or company engaged in the haulage of goods. 

  • A truck, lorry (vehicle used to transport heavy goods) 

  • A person or thing that hauls another person or thing. 

  • A miner who hauls coal from the coalface to the bottom of the shaft. 

  • Someone who makes a haul video. 

tractor trailer

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