As vehicles speed by on gravel roads, they leave in their wake heaps of dust. Dust can endanger the lives of people nearby and also affect natural habitats. Some of the health conditions and diseases that could be caused by dust include allergies, skin conditions, and respiratory complications.
There are various ways to reduce the amount of dust on gravel roads. Below are eight popular methods of dust control for gravel roads.
1. Increase the Road’s Surface Moisture Content
Moisture is critical in compacting particles on gravel roads. You can increase the moisture content on gravel roads by using effective dust control products, by applying deliquescent salts or by spreading the water.
Deliquescent salts attract water and are a form of dust palliative. These salts include calcium chloride, magnesium, or chloride. They are good at absorbing water from the air.
Gravel roads treated with these salts have a higher water content than untreated ones. The disadvantage of applying these salts, however, is that the roads become slippery and wet. They also cause corrosion on vehicles. In any case, once the rains come, the salts are washed away from the roads. Ideally, after one or so years, the salts should be reapplied since the rains could have washed them away.
2. Limit the Number of Vehicles Per Gravel Road
One way to minimize dust on gravel roads is to reduce the number of vehicles using it. While this is not always practical, people can be encouraged to walk. Besides dust reduction, walking is also good for your health. Encourage citizens to only use their vehicles on a gravel road when it’s absolutely necessary.
3. Keep Heavy Vehicles off Gravel Roads
Besides reducing the number of cars on a gravel road, another solution to control dust on roads is by restricting the types of vehicles using it. Heavy vehicles should, as much as possible, stay off gravel roads. They blow up billows of dust that linger long after they have disappeared into the horizon.
4. Impose Speed Limit Restrictions on Gravel Roads
Nothing blows up dust more than a speeding vehicle. According to studies, a specific type of dust called PM10 increases with vehicle speed. By reducing a vehicle’s speed from 40 mph to 20 mph, dust emissions are cut by 65%.
One way to enforce speed limits is to install speed limit signs on gravel roads. Constructing speed bumps and drainage channels across gravel roads also discourage drivers from flooring the gas pedal. However, enforcing speed limits takes individual responsibility and adherence to the law.
5. Adopt Better Road Designs
Having well-designed gravel road drainage can substantially minimize dust. A poorly drained gravel road ends up with puddles. As water floats, fine particles from the soil under the road comes out. As traffic intensifies, this solution is converted into mud or dust. Besides, stationary water next to a gravel road saturates the roadbed, which is a significant cause of potholes.
Once the fine particles are blown or washed away, the bigger particles are unanchored and shoved to the roadside, necessitating prohibitive road resurfacing. Even if one was to treat such a road with a dust palliative, its performance would depend on a smooth driving surface and the road shedding water.
6. Water the Road
Particles tend to stick together when there’s moisture on the surface of gravel roads. You can increase the moisture content on these roads by watering them. One watering may be sufficient for a couple of days, or just a few hours, depending on the weather. This method is appropriate since water is readily available in most areas. However, in small communities, moving and spreading the water on gravel roads can be quite a daunting task.
Larger communities are likely to afford water trucks to fetch water from local water supplies and water the unpaved roads. Water is, however, a stop-gap measure of reducing dust on gravel roads. For best results, apply light watering on unpaved roads instead of heavy, less frequent watering.
7. Covering Dirt Roads with Gravel
Gravelled roads are less dusty than dirt roads. There are local road maintenance experts who can provide information on effective methods of gravelling roads in a way that minimizes dust. However, although gravel roads are better at handling dust than dirt roads, air currents caused by cars will still blow loose particles into the air, causing dust.
New gravel should be anchored to the surface of the road. This can be done by incorporating gravel with soil adhesives or aggregate mixes.
Geotextile fabrics can be used to prevent losing gravel due to the presence of soil pressed under the road. The materials feature polymer threads that have incredibly high tensile strength. They are also available in designs that allow or bar water from flowing through, but not fine soil.
8. Binding Particles Using Chemicals
This type of dust palliative aims at binding fine particles together or binding them onto bigger particles. The chemicals used include synthetic polymers, organic non-petroleum, electrochemical stabilizers, and petroleum-based products.
Controlling dust on gravel roads requires a combination of interventions. Some of these are mechanical, while others are chemical. Whatever method you use depends on your budget and the expertise available.