Roadways throughout America receive plenty of wear and tear simply from the number of cars and trucks using them everyday. Add to that the cold, hard winters found throughout much of the northern United States and you have roadways that require even more attention. One of the ways to reduce the damage is to use permeable or porous paving. Below is a brief definition of permeable paving and four reasons its use is well warranted.
Permeable paving allows moisture, whether from rain or snow melt, to seep through to the soil below. Technology has allowed manufacturers to create paving that looks almost the same as their impervious counter parts, such as concrete, asphalt, and paving stones. Impervious pavement is designed to keep water away from the substrate. On new roadways, this works quite well, but as the roadway ages cracks and other imperfections defeat the purpose. According to the Stormwater Report, dark colored permeable pavement appears to need less winter maintenance than the light colored version.
Cities and municipalities usually prepare their roadways before a storm using deicing salt. The intent is to melt the snow before it has a chance to accumulate, leaving the roadways drivable. Permeable paved roadways usually need more deicing salt initially because when the snow melts the resulting water and salt mixture seeps through the surface. Salt clings to the minute spaces between the aggregate, the materials used to create the pavement, leaving much of that salt close to the surface. Additional snow is melted by this method of "salt recycling." On impervious pavement, the salt water usually runs off the roadway into storage drains, leaving less salt for the next round of storms. The roads need deiced ASAP to prevent ice and snow build-up.
Black ice creates one of the most dangerous driving conditions, because you usually can't see it. Bridges, overpasses, and freeway on and off ramps are typically more susceptible because they are, at least in part, suspended in mid-air. Water pools on the roadway and freezes into a clear ice sheet thanks to cold air coming from above and below. Black ice also forms on sections of roadways built on solid ground. As the snow melts and refreezes, clear sheets of ice form. The solution in either scenario is typically to break out the snowplows and deicing machines. Water is less likely to pool on permeable pavement, because it has an "escape route." By reducing the amount of pooled water on the roads, you are reducing the black ice problem.
In the northern states, potholes tend to be hidden under ice and snow during the winter. The damage revealed after the spring thaw shows that potholes are often an even bigger problem than in the south. A pothole starts with water seeping into tiny pavement cracks and then freezing. Each time this happens the cracks widen. As cars drive over them the edges chip off, creating a noticeable hole. In permeable paving, the water is intended to seep through the pavement and into the substrate. It doesn't usually stick around long enough to freeze. Even if the minute drops of water do freeze, the spaces within the aggregate are so tiny that cracks rarely form.
Water running off a roadway and into a drainage ditch carries traces of salt, engine oil, gas, and anything else that happened to spill on that roadway. Depending on where you live, that water could go to a treatment plant before being discharged or could simply be headed for the nearest body of water. Permeable pavement allows the water to filter its way through the soil. Most pollutants are usually eliminated during this process. For more information, contact a road construction company like Lien Transportation Co.