Asphalt roads are pollution fighters on two fronts

IN ITS RAW APPLICATION FORM, asphalt is thick, black, gooey, sticky, and really smelly. In its useable form, though, compacted and cooled for the motoring public, asphalt actually is a 24/7 pollution fighter.

How so? Well, studies have shown us that asphalt is the quiet pavement that fights noise pollution. In addition, asphalt roads are air pollution fighters when they’re used to replace dirt and gravel roads.

The Asphalt Pavement Alliance makes note of U.S. and European research that shows “quiet asphalt” technology reducing highway noise by at least 3 to 5 A-weighted decibels, or dB(a), with noise reductions of 3 to 10 dB(a) being common. According to the information passed along by the alliance, reducing noise by 3 dB(a) is about the same as doubling the distance from the road to the listener, or reducing traffic volume by 50 percent.

“There is no better way to reduce road noise than to treat the problem at its source,” the alliance states. “By paving roads and highways with asphalt, the noise inside homes and businesses can be significantly reduced.”

Approximately 94 percent of the paved roads in America already are surfaced with asphalt. Almost all of the remaining paved roads have been constructed in concrete.

There are, of course, roads that are neither in asphalt nor concrete, and those are the ones that actually make up the bulk of roads in America. Approximately, 70 percent of U.S. roads are unpaved, and the U.S. Environmental Protection Agency reports that about 40 percent of all the dust particles in the nation’s atmosphere come from these unpaved roads.

The U.S. Forest Service estimates that a single vehicle traveling one mile each day down an unpaved country road will generate nearly a ton of dust over the course of a year. That’s the impact of just one vehicle on a gravel or dirt road! Imagine the dusty conditions if this road happens to be well traveled! According to the Forest Service, dust in the air can travel up to 500 feet before it eventually settles down.

If dust particles generated by traffic on unpaved roads can be kicked into the air with that kind of volume, they easily can wind up in nearby homes and be the source of health problems, ranging from coughing spells to asthma and bronchitis.

In a 2011 report, The World Bank went into some detail about the environmental and health risks associated with traffic-generated dust from unpaved roads. The dust from gravel roads often is fine enough to pass into the lungs and cause serious irritation or damage. People with existing respiratory conditions, such as asthma, and young children particularly are vulnerable to this dust, the report states.

The report also focused on the financial impact of road dust and how it damages crops and livestock, thus reducing agricultural production and any profits the nation’s farmers might enjoy.

There’s a motoring safety factor to consider, too. Anyone who has been behind a vehicle on a dirt road knows how poor the driving vision can be with all the dust in the air. A moment of inattention by you and a sudden stop by the car or truck ahead of you are the makings for a potentially serious accident.

So, what’s the bottom line? The next time you’re in a road construction zone and pass by an asphalt paving or repaving project, don’t mind the smelly goo too much. The bad smell won’t last long, but the pollution-fighting impact of the pavement could last a lifetime.

Article sources: The Fence Post, World Bank research, and the Asphalt Pavement Alliance.