This topic has come up in the past in conjunction with other discussions. However, I believe that it deserves undivided attention. As Spring is arriving, it is time for drivers to start crawling around under their trucks to assess the damage caused by the "brine" mixtures that various states are applying to the roads to reduce icing. These chlorides apparently mix with the the water on the roads, form a vapor and then penetrate every unprotected area on the underside of the truck. This results in excessive rusting, the corrossion of electrical connections and the cracking of brake linings. (If the brake linings are cracked, you will be "out of service".) Take the time to take a good look underneath. You may also want to check the wiring for any cuts or openings. If the copper wire is green, you need to repair it. The rusting is so bad on my truck that I will be pulling off the box and sandblasting and repainting the the truck frame this summer.
Take care, and drive safe.
Take care, and drive safe.