When winter storms dump snow and ice on the highway, truckers welcome the sight of snowplows and salt-spreaders, also known as gritters, clearing a path. But while the inclement weather tag team performs an invaluable service for highway users, it also often exacts a subtle but nasty toll in the process. When the gritters are spreading salt or other chemicals, they are also spreading the cancer of corrosion.
 | How Does Salt Work? |
| Salt is the most common substance used by state and municipal road crews to clear the thoroughfares of ice and snow. Here is how the particles perform thier magic:
 After being spread on an icy surface, salt begins to lower the freezing point of water. High concentrations of salt improve the chance of dropping the temperature required for water to turn to ice, which is normally 32°F.
Melting starts immediately when salt makes contact with the frozen precipitation. Heat is created in the melting process — the latent reaction of fusion. This produces water that dissolves more salt and, in turn, produces further melting.
The rate of turning snow or ice into water depends on the surrounding air and ground temperatures. Other factors include the size of the salt particles and the amount of mixing caused by traffic.
Source: Salt Manufacturers’ Association
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The price of safe winter passage carries with it the potential for untold damage to the underbellies and other metal parts of big rigs. Studies put the nation’s annual tab for plowing and sanding or salting roads at $2 billion. Add to that at least $5 billion in environmental harm and corrosion damage to trucks, buses, cars and road surfaces.
For truck owners, some relief has arrived in the form of better protection for truck metal and less harmful alternatives in the deicers.
However, not everyone thinks things are getting better. Although the corrosion problem has been around for more than 20 years, some fleet maintenance managers think it is getting worse. They believe the situation is going downhill despite steps by manufacturers to make parts less vulnerable to the onslaught of pollutants, sand and deicers — such as sodium chloride and calcium chloride — used to keep roads open during ice and snow storms.
For the full story, see the Oct. 9 print edition of Transport Topics. Subscribe today.
