RepairPal Blog:

I was driving on the entrance ramp to a highway yesterday when a huge crater suddenly presented itself before me. I was going about 55mph and the double lane was tapering into a single lane, so there was nothing I could do to avoid it. I braced myself and cringed when I went over the pothole, certain it would rip the entire suspension from my vehicle. It didn’t, but it sure sounded and felt like it.

Most of the time, I am appalled at the state of roads around me. It seems like every road I drive on is bumpy and falling apart. Even the newly paved road they installed near my house last year already has a huge chunk out of it.

What causes potholes, I wonder. And besides driving like a drunk to swerve around them, what can I really do about them?

How Are Potholes Created?
Apparently, most roads are built in layers. The first layer can consist of gravel, compacted earth, or in older cities, the first layer could be made of brick. These layers are then covered with asphalt, which has that wonderful smell we all love. Asphalt is a blend of tar, oil byproducts, and aggregates (stone, gravel, and sand). The purpose of asphalt is to repel rain and snow.

The reason potholes occur is because the asphalt eventually cracks under the pressure of heat and moisture and because of the constant stress of traffic. When the asphalt cracks, moisture (rain or snow) gets into the underlying level of gravel or dirt. Then, when cold temperatures come, the moisture on this first level expands, which pushes the gravel outward. When it recedes, a hole is left in the road. People driving over them constantly only makes it worse.

When the asphalt finally collapses, we get a pothole. The problem is exacerbated by poor road construction and the increased pressure of tractor trailers.

How Are Potholes Fixed?
There are two different methods for repairing potholes and they are very similar to how dentists fill cavities. First, there can be a temporary fix to the pothole. Called a “cold winter mix,” once the hole has been cleared of debris, soft asphalt is poured into it. Sometimes a layer of gravel is added to increase the strength of the bond, even though this method is only meant to be a short term fix.

The more permanent fix is called a “hot summer mix.” The idea here is to apply the fix when the road is warm and dry. When road crews do these permanent fixes, they reroute traffic and spend more time preparing the road surface. Then, a combination of road-grade asphalt and aggregate is poured into the hole. Finally, the crew uses an asphalt compactor to compact the patch until it matches the road surface around it.

How Can I Avoid Potholes?
Sadly, the only thing you can do to avoid potholes is to always drive on pristine roadways, which we all know is impossible. You can contact your local DOT and request that they fix the potholes in your area. If you own your own property with roads on it, you can always fix potholes yourself, though it can be very time consuming and expensive.

Other than that, there’s not much you can do except try to drive around them—or start walking!