Road Salt

Now that winter has arrived in southern Ontario, we can expect to spend the next 3 or 4 months covered in a pasty layer of white salty mess. The first usage of salt on roads was by Detroit in 1940. Salt was used because a large deposit was discovered in the Detroit area in 1914. Salt was found to be more effective than sand for improving traction on roads. A 1992 study  conducted by Marquette University in Wisconsin found that road salt reduced crashes by 88 percent, injuries by 85 percent, and accident costs by 85 percent. 

Today salt isn’t just used on roads. It’s found on sidewalks, driveways, wheelchair ramps, parking lots and playgrounds. It’s become the de facto safety measure when winter strikes. 

The problem is that in almost all cases, too much salt is used. Salt is most effective on cold dry winter surfaces that are covered in ice. If conditions are too wet, the salt dissolves and becomes useless. Too much snow and the salt melts to the surface rendering it useless. Yet, you see the salt truck out spreading it’s load on wet road. The maintenance company spreads so much salt in the mall parking lot that it crunches as you walk by. 

Salt is an oxidant speeding up the rusting of metal on your car. It stains fabric, turning those Uggs from beige to cream coloured. 

Salt gives us grip. It helps us because we don’t slip, fall and possibly hurt ourselves.

What happens if a spot gets missed and a thin layer of black ice forms on the sidewalk? It’s likely that we’ll slip. We’re not used to walking on ice. 

What if one day the world runs out of salt? Will cold climates descend into chaos? Unlikely. We’ll probably learn how to walk on ice. We’ll take our time, maybe even help each other. We may fall, but over time we’ll learn how to fall properly. We’ll become good at walking on ice. 

How much salt are you laying down in your classrooms or even as a parent?

http://news.nationalgeographic.com/news/2014/02/140212-road-salt-shortages-melting-ice-snow-science/