Everyone hates potholes.
Drivers can make dangerous, sudden moves to avoid them. If a street is really loaded with potholes, they slow down traffic. Then there’s vehicle damage: The American Automobile Association reports that these pesky dips and depressions cost U.S. drivers some $3 billion per year.
Birth of a pothole
Potholes typically form when water works its way underneath asphalt through surface cracks. The water, often refreezing and melting several times, destabilizes the soil underneath. As traffic passes over, the top layer of asphalt eventually gives way.
Potholes are common in states where roads are subjected to snowmelt, but streets in flood-prone areas are also susceptible.
A seal in time prevents nine
The surest way to prevent potholes is to seal cracks as soon as they form. But with many states and local governments strapped for cash, that doesn’t always happen. Another prevention strategy is to ensure a quality installation. Dried out or poor quality asphalt mix can accelerate crack formation.
Filling the gaps
Drivers can choose a car with anti-pothole technology, but there's not much they can do to avoid hitting potholes. The asphalt industry and various research teams are searching for ways to speed up pothole repair.
Still in wide use during the summer months and in warmer states is the traditional hot mix repair that takes several hours to dry. In snow-prone states, however, there are now cold mixes. Dubbed "throw and go," crews can use them to temporarily fill the holes, even in winter. After compaction by a tire or some other piece of heavy equipment, the road can be used almost immediately. Some cold mix products, such as EZ Street Asphalt, are promoted as permanent patches that don’t need a follow-up hot-mix application later on.
Another solution has crews heating up the asphalt around a pothole with an infrared heater and then mixing new asphalt in with the old, leaving a patch with no seams.
Even if money weren’t tight, crews can’t get to every pothole right away, so a team of former Case Western University students has developed a temporary patch in the form of a bag of non-Newtonian fluid that hardens as cars drive over it. It's being tested now and could come in handy in colder climates, where road crews often suspend winter operations.
Kim Slowey