What are they pre-treating the roads with nowadays before a snow? It leaves parallel lines asif the road were scored. Actually, it looks like rows of salt trails from a bunch of slugs! What is this residue? Or, shall I say “pre-residue”?
Depending on where you live, some of the more common chemical road treatments are: sodium chloride (salt), magnesium chloride, calcium chloride, calcium magnesium acetate and potassium acetate.
Here in Colorado magnesium chloride seems to be the chemical of choice. But that leaves the roadways evenly covered in a white powder, with no pattern that I have observed. My WAG would be that the parallel lines would be an artifact of the application process, not the chemical itself.
It’s a liquid pre-treatment and is done as a cost saving measure to extend salt reserves. It caught on in my area after the 2008/2009 winter price spike in salt.
I would venture a wild guess that the thing that look like rows of salt trails is… a row of salt trail.
i would assume they pre treat it so snow doesn’t start accumulating on it, making subsequent removal easier.
Last winter, a town in Iowa ran low on road salt, and used garlic salt on their roads, to stretch out their supply.
The parallel lines are there because of the way it spills out of the truck. If they poured out a continuous sheet, it would take a LOT more of it.
Kept the vampire population in check, too.
Oregon, Washington, Montana, Idaho and BC now use mostly magnesium chloride rather than regular salt. It is usually applied as a liquid and that is what the lines on the road are, trails from the liquid sprayers.
The reasons why magnesium chloride is better than regular salt are listed here: