Potholes: Everyone's Favorite in Spring

Okay, okay. We know potholes aren’t actually everyone’s favorite thing when spring rolls around (they might even be up there with cold, cloudy days in May). But if you are one of 83% of Americans who drive a car regularly (according to this 2018 Gallup poll), you do have to deal with them in your travels… especially around the time that winter transitions to spring.

But why do potholes only seem to be a big problem when the weather starts to get warmer? Well, that’s because potholes result from a combination of water going through freeze-thaw cycles, as well as traffic on the roadway. 

Our roads are made of water-resistant materials. Typically, water will run off of the road and to the shoulder, or other drainage areas. But, as a road ages and more traffic passes over it, it will develop cracks over time. Water is then able to seep into and underneath the pavement. 

In the spring months, this spells trouble for our roads. If water is able to seep into the materials and soils below, it will freeze when temperatures dip below 32 degrees Fahrenheit. When water freezes it expands (think about an ice cube tray), and the area of the pavement rises with this expansion. However, when the frozen ground below this raised area of the pavement melts, it will usually leave a gap, and this creates a weak spot in the roadway. As traffic passes over it, pieces of the road will weaken further and can even break apart… and voila, you have a pothole. 

You can easily think about how this process will repeat itself in the spring months, as temperatures frequently fluctuate above and below 32 degrees. Spring also features a good frequency of weather systems which bring rain and/or snow into the picture. 

But what about in the winter? Does road salt affect this process? 

The short answer is: yes. Road salt lowers the freezing temperature of water, which is its primary use in the winter months (in order to melt snow and prevent snow-covered roadways). However, this lowered freezing temperature can introduce more freeze-thaw cycles (for example, if the freezing temperature is lowered to 15 degrees, freeze-thaw cycles will occur around that point instead of around 32 degrees). This can result in pothole development in much colder months, when it ordinarily would have not been an issue. 

Road crews try and tackle this by filling in the potholes, but this can be difficult. In order to prevent the pothole from redeveloping, you have to seal the pavement to prevent water from seeping in again. 

So, at the end of all this, what can we do (as drivers) to avoid potholes… or at least limit the amount of damage they cause? Aside from the obvious method of driving around, the Michigan Department of Transportation has some recommendations: 

1. Before heading out on the road, make sure your tires are inflated appropriately. Over- and under-inflated tires are most prone to damage. 
2. Maintain a following distance that allows you time to react, either to the car in front of you or to the approaching pothole. 
3. Apply your brakes before hitting the pothole, then release them as you roll through it. This gives your suspension the full range of motion to absorb the pothole hit. 
4. Steer straight into the pothole. This may seem counter-intuitive, but if you try to avoid it too late and hit the pothole at an angle, this can transfer the energy in ways that are more likely to cause damage to your vehicle. 

While these obviously won’t help as much as avoiding one altogether, these tips may help limit damage. Additionally, many states and towns have pothole reporting programs that you can utilize to let the right people know.