This winter has been ruthless. Heating bills have been through the roof, nobody (with a decent head on their shoulders) has worn flip-flops in months, and the streets of Chicago are all lined with potholes. Those awful potholes appear every winter, and most people know old Jack Frost is to blame. But have you ever asked yourself, “How do potholes form exactly?” Lucky for you, Perillo BMW has the answer.
Potholes form when groundwater gets into the ground under the pavement, typically from small cracks in the surface. When this water freezes, it expands, much like water in an ice tray expands when it becomes ice in the freezer. By default, the pavement will react along with the freezing water, bending and cracking and, well, expanding. This process weakens the pavement. Then, when things warm up and the ice melts, the pavement contracts, leaving a few gaps in the surface. More water can now get in and freeze, and the vicious cycle repeats.
Eventually, as heavy cars and even heavier trucks drive over the weakened surface, the pavement will begin to break down and chip away, creating the pothole we all know and love.
But wait, it gets worse. As your shoes and the lower portion of your car are probably well aware this winter, the city likes to bring out salt to combat the wintry weather on the roadways. Salt lowers the temperature at which water will freeze (but not by much, as this polar vortex has taught us). Adding salt to the mix creates an artificial cycle of freezing and thawing, allowing even more instances of weakening the pavement to occur and leaving us with even more beautiful potholes.
Unfortunately, these monsters are inevitable, so as you navigate the roadways this spring, keep a lookout for all the potholes and dodge the ones you can. Good luck, and happy slaloming!