There are a variety of types of noise barriers that are regularly used to reduce noise pollution. Noise barriers are any outside structure that are used to block sound waves from roads, railroad tracks and industrial areas. They can be made of natural or manmade materials. To be effective, these barriers must take a variety of factors into consideration.
When engineers are designing noise barriers, they look at the amount of traffic on a road, the way that the road is shaped, how the land lies around the roadway and what type of materials the road is made from. Noise barriers are expensive to build and install. In particular, barrier walls that run alongside interstate highways can mean miles of construction. For this reason, noise barriers are most often constructed in areas where the roadways pass through residential areas.
Scientific research has shown, time and again, that living with excess noise can be damaging to the health of residents. Excessive noise can lead to hearing problems, elevated blood pressure, problems sleeping and an increase in general stress levels.
There are two basic types of noise barriers. The first are made from earth, on site. This is the least expensive option. The earth is available on the job site and at no cost, so the only cost is the labor of constructing the barrier wall.
Often there is not quite enough material on the job. In this case, the property owners alongside the roadways often allow for the use of some fill material from their property. This provides the added benefit of lowering the ground level of the property, further reducing noise on the property.
Barrier walls can also be constructed of manmade materials. They may be concrete, steel, plastic or composite materials. These materials are very effective at preventing sound waves from traveling off of the roadway, but have other drawbacks.
The major drawbacks of manmade noise barriers are the cost, aesthetics and the need for specialized drainage solutions. The cost of several miles of noise barriers can quickly become astronomical. Aesthetics is a concern as well, as miles of steel or concrete walls can be very unattractive. Finally, placing a noise barrier beside an existing roadway can cause changes in the drainage on the roadway, leading to water pooling during rainy weather. All of these factors must be taken into careful consideration when building a noise barrier.