A driver’s natural born enemy, potholes can pop up any time of year. However, if you live in an area with particularly bad winters, it may seem like they show up overnight during the cold months, wreaking havoc on your alignment or causing pothole damage to your car.
Don’t worry — you’re not imagining it! Freezing weather brings out the worst in roads, and here’s why:
The Anatomy of a Road
Most roads are made of three layers: soil, a sub-base of stones and an exterior layer of small rocks compressed in an emulsifying petroleum byproduct, like tar. This top layer is meant to repel water, but it can be compromised by heavy traffic, age and extreme weather. All of these factors can leave small cracks in the surface, allowing water to seep in.
When this happens, the water carries away pieces of the base and sub-layer, destabilizing the structural integrity of the road and making it susceptible to the weight of normal traffic. When a car rolls over the brittle patch, the road caves in. This is why potholes often seem to appear overnight. Once the top layer has been severely compromised, a pothole can grow rapidly.
Water is Weird
As a liquid freezes, it typically condenses. However, water is a little different. Above 4°C (39°F) and below 0°C (32°F), water acts like most substances, expanding as it heats and condensing as it cools. But from 0–4°C, the reverse is true.
It’s this unique feature of water that contributes to the formation of potholes. As mentioned, water seeps into small cracks and holes in the road’s surface when it’s in liquid form. As it freezes, solidifies and expands in the cold, it displaces the road’s sub-layers more than normal water damage would.
The Perfect Storm
As the freeze-thaw cycle happens over and over again, larger pits form and more water gets into the road. Add road salt into the mix, and there are even more ways for potholes to gain footing. Salt lowers the freezing temperature of water, which means there is increased opportunity for freeze-thaw cycles to happen at colder temperatures.
In short, you are not paranoid for thinking that, come winter, mechanic’s shops are busier than usual fixing pothole damage.
Preparing for a Rocky Winter
Because moisture sticks around in the form of ice during the winter, it’s not a particularly good season for pothole repair. There are different approaches to solving this problem — many cities are opting to lay down a temporary fix to minimize vehicle damage during the cold months and then following up with a more permanent solution when spring arrives.
In the meantime, potholes are not only frustrating, but they are also dangerous, especially when masked by snow or ice. The best way to stay safe is to stay aware, make mental notes of problem areas on roads you travel and stay on top of proper tire inflation and alignment. If you hit a big pothole and suspect damage, see a mechanic as soon as possible to get your vehicle back on the road in fighting form.
Check out all the steering and suspension parts
Photo courtesy of Flickr
Blair Lampe is a New York-based professional mechanic, blogger, theater technician, and speechwriter. In her downtime she enjoys backpacking wherever her boots will carry her, rock climbing, experimental theatre, a crisp rosé , and showering love on her 2001 Sierra truck.