Did you know that many roads in the US are unpaved? That’s right. Millions of Americans travel on dirt roads every day. However, most are in rural areas with lower traffic volumes.
These roads are cheaper to build, but their major drawback is dust clouds. The dust reduces visibility, which could lead to accidents, and inhaling it can cause respiratory problems, especially for those with asthma or allergies. So, how do you reduce dust on roads?
Dust on unpaved roads is a nuisance, but solutions exist. The best solution depends on your budget, climate, traffic volume, and environmental sensitivity. Calcium and magnesium chloride are the most effective methods.
Let’s explore all the best methods to clean dusty roads.
Applying Water to the Surface
Water application is one of the most common methods of reducing road dust. Applying water to the surface binds dust particles together, temporarily reducing dust clouds. The benefit of using this method is that water is easy to obtain and safe for the environment and workers.
However, water evaporates quickly, especially in dry climates, so this is a short-term solution. You’ll need to reapply frequently. Moreover, excessive watering can lead to soil erosion, resulting in potholes.
Using Calcium Chloride
Calcium chloride is the most effective method of reducing dust on the road. It is a hygroscopic material that attracts moisture from the air and creates a damp layer on the road surface. This dampness prevents loose dust particles from becoming airborne.
It works immediately after application, but you may need to reapply throughout the season, especially after heavy rains or extended dry periods. Reapplication helps build long-lasting results. Because calcium chloride remains liquid, it dampens roads even in hot, dry conditions.
Calcium chloride for dust control will reduce erosion, translating to fewer potholes and less maintenance. However, remember that runoff from calcium chloride can contaminate nearby soil and waterways. Chloride ions can harm plant life and disrupt aquatic ecosystems. For this reason, it should not be applied near sensitive environmental areas.
Using Magnesium Chloride
Magnesium chloride works like calcium chloride to control dust on unpaved roads. Because it is hygroscopic, it attracts moisture from the air and clumps dust particles together. These larger clumps are less likely to be kicked up by vehicles.
Like calcium chloride, magnesium chloride dust control solutions can reduce erosion and pothole formation, keeping roads hard and durable. It can be applied as liquid, flakes, or pellets. While very effective at dust control, magnesium chloride is harmful to the environment, though not as much as calcium chloride. Runoff contaminates nearby soil and waterways.
Unfortunately, it is more corrosive to metals than calcium chloride, so it can damage vehicles and guardrails if they are in contact with it. Moreover, it solidifies in hot, dry conditions and provides minimal dust protection.
Using Lignosulfonate
Are you looking for a more environmentally friendly solution to road dust? Lignosulfonates are precisely what you need. Lignosulfonates are natural, water-soluble polymers derived from lignin, a complex organic compound in plant cell walls. They are a byproduct of the sulfite pulping process of paper manufacturing.
When used for dust reduction, lignin attracts water vapor from the air and creates a slightly damp film on the road surface. This glues dust particles together. Over time, the sun’s heat makes the lignin completely insoluble, resulting in a tough, dust-controlled, water-resistant surface.
Unlike chlorides, which corrode vehicles and harm nearby ecosystems, lignin sulfonate is gentle on cars and the environment. It breaks down naturally and doesn’t threaten plants or aquatic life. However, it lasts less than chloride and is more expensive.
Adding a Gravel Cover to the Road Surface
Adding a gravel cover to the road surface can also control dust. The larger gravel pieces prevent finer particles from becoming airborne. However, this method requires regular maintenance as the gravel can loosen over time and become part of the dust.
Traffic Management
Traffic management can also reduce dust, but only to some extent. This can be done by reducing speed limits or restricting traffic volume. Lowering speed limits minimizes dust particle kickup.
For instance, reducing the speed limit from 45 miles per day to 35 mph can reduce dust by 22%. In some cases, you can also restrict heavy vehicles from using the road to prevent damage to the road surface and base. This leads to dust generation.
Paving the Road with Asphalt or Concrete
Paving the road with asphalt or concrete is the best way to eliminate dust problems. Paved surfaces create a solid barrier, preventing soil particles from breaking into dust. While paving is a long-term solution, it’s also the most expensive option and may not be viable on rural roads with minimal traffic.
