The Dart Tractors pulling the triple trailers in California were a big thing many years ago.I don't think Dart or Payhauler trucks are around anymore as Dart was sold to Unit-Rig Company which became a part of TEREX CORPORATION.  TEREX also aquired Payhauler trucks. I think RIMPULL is still in business and rebuilt a lot of DART trucks.

The World's Largest Salt Shops, The Most Impressive Trucks of the salt mines you must see.