Oak Hill, WV (WOAY-TV): We haven’t had to deal with it much in the last few years, but this winter will be a completely different story.
Potholes…. the reason drivers need their alignment adjusted after driving fast over one of these things!
If you look really close at the pavement, there are small holes that allow water from melted snow and ice to seep in. The sun is the driving force behind melting the snow and ice because as soon as it hits the dark colored pavement, temperatures usually skyrocket.
Take this example (in the video) where the pavement temperature is about 10 degrees warmer than the air temperature following a winter storm. On a typical winter day without any precipitation moving in or Arctic front crossing a roadway, pavement is warmest during the late afternoon.
On a clear night, roads can readily radiate heat away (if a snowpack is nearby), so paved surfaces can get colder than the air above it.
How do potholes form? Melted snow and ice during the day easily find their way into the pavement. Then, that water freezes overnight or when an Arctic blast arrives. Water expands and takes up space when it freezes, so this ends up busting bits of the pavement away.
When the sun returns the next day, pavement heats up quickly and the ice melts, but the water never dries up because the top layer of pavement shelters the water from the sun.
The next night, that water freezes and expands, busting through even more pavement below the surface. Now, little voids develop in the pavement. The freeze/thaw cycle breaks off more bits of pavement each night and day, gradually weakening a small portion of the paved road. The more frequently the cycle occurs, the weaker the pavement becomes.
After a week or so of this vicious cycle, the fractured pavement can’t support the weight of motor vehicles and potholes form.
Given the snow we’ve already seen and prospect for an occasionally snowy back half of winter, expect more ruts in the road and pothole repairs for road crews.
