Winter's true grit: Road Treatment materials

In winter, we often see trucks spreading stuff on icy roads to keep drivers safe. While most people recognize these trucks, many don't know what they're spreading or why cities pick certain materials over others. Let's look at how these winter road treatments affect both our safety and city spending.

Rock salt (sodium chloride) is what most cities nationwide put on winter roads, but it's the sand and small rocks that make a difference in traction. Traditional road sand is made of finely crushed stone between 1/8 and 1/16 inch in size, about as thick as two sheets of paper. This sand works right away and helps cars grip the road. While sand is cheap and easy to find, it can cause problems by blocking street drains and creating extra work for cleanup crews in spring. Cars and trucks also push the sand off the road quickly, so workers need to keep adding more of it throughout winter in areas of heavier traffic.

Cities with large budgets sometimes use crushed granite instead of regular sand. Granite works better because its sharp edges grip ice well, and it stays on the road longer than sand does. While granite costs a lot more - sometimes three times as much as regular sand - it's better for the air we breathe because it doesn't break down into dust as easily.

Some cities mix different sizes of small rocks and sand, from tiny grains up to pieces about as big as a pencil eraser. Crushed rock, also known as aggregate, is one of the more common. It also serves as a base for driveways, parking lots, and paving. Washed gravel is used for playgrounds, decorative uses, and tank bedding and is not as effective for road traction. Shot rock is broken rock created by blasting and is used by the State of Alaska in some areas. The problem with any gravel is that bigger pieces can crack windshields when cars drive over them, and they're harder to clean up when spring comes.

Winter road sand might look darker or thicker sometimes because it has bits of dirt mixed in when it's dug up and processed. While this makes the sand look different, it doesn't change how well it works on icy roads. What really matters is how big the sand pieces are, how sharp their edges are, and how hard the sand is.

When cities run out of sand and salt during winter, it can cause big problems and cost a lot of money. This happens to cities when winters are much harsher than had been predicted. When their usual suppliers run out, cities need to buy from other places, sometimes very far away. This costs much more money because of emergency prices and transportation costs. Cities might also have to use whatever they can find, even if it's not the kind they usually prefer.

When cities run out of their usual road materials, they might have to use different ones instead. If a city normally uses crushed rock pieces, they might have to switch to regular sand, which is of lower quality and function. This can cause problems because the roads might feel different to drive on than they have been, and workers have to use different ways to spread the materials. Cities sometimes pay twice (or more) as much money for emergency supplies. They might also have to pick which roads to treat first, which can make some people upset about unsafe roads in their neighborhood.

Taking care of winter roads isn't as easy as just throwing sand on ice. Cities plan what materials work best, how much they cost, how they affect nature, and if they can get enough when needed. As our winters become more unpredictable due to changing weather patterns, cities need to plan carefully for how much material to store and use. When we understand these challenges better, we can see why it's important to support our cities in paying for quality products.

Christian M. Hartley is a 40-year Alaskan resident with over 25 years of public safety experience and public service. He runs a freelance business, Big Lake Writer, from home in Big Lake that he shares with his wife of 19 years and their three teenage sons.