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Encyclopedia > Noise barrier
The sound tube in Melbourne, Australia, designed to reduce roadway noise without detracting from the area's aesthetics.
The sound tube in Melbourne, Australia, designed to reduce roadway noise without detracting from the area's aesthetics.

A noise barrier is an exterior structure, designed to protect sensitive land uses from noise pollution. Other commonly used terms for noise barrier are: "soundwall", "sound berm", "sound barrier" and "acoustical barrier". Noise barriers are the most effective method of roadway noise mitigation, and mitigation of railway and industrial noise sources (other than cessation of the source activity or use of source controls). In the case of surface transportation noise, very little can be done to further reduce the source noise intensity (other than increase the percentage of hybrid vehicles and electric vehicles, a strategy that works only at low to moderate traffic flow speeds). Extensive use of noise barriers began in the United States after noise regulations that were introduced in the early 1970s. Download high resolution version (1280x960, 269 KB)Heading through the Sound Tube on the Tullamarine Freeway in Melbourne, Victoria, Australia. ... Download high resolution version (1280x960, 269 KB)Heading through the Sound Tube on the Tullamarine Freeway in Melbourne, Victoria, Australia. ... CityLink is a tolled freeway system in Melbourne, Victoria, Australia. ... Melbournes CBD has grown to straddle the Yarra River in three major precincts. ... Land use is the pattern of construction and activity land is used for. ... Noise pollution (or environmental noise in technical venues) is displeasing human or machine created sound that disrupts the environment. ... Roadway noise is the most prevalent form of environmental noise. ... Noise mitigation is a set of strategies to reduce unwanted environmental sound. ... A hybrid vehicle (HV) is a vehicle that uses two or more distinct power or fuel sources such as: An on-board rechargeable energy storage system (RESS) and a fueled power source for vehicle propulsion Human powered bicycle with battery assist A sail boat with electric power[1] The term... this is wikjipeda A streetcar drawing current from a single overhead wire, returning current through the rails and ground An electric locomotive, taking power through a pantograph An electric vehicle, or EV, is a vehicle with one or more electric motors for propulsion. ... Noise regulation includes statutes or guidelines relating to sound transmission established by national, state or provincial and municipal levels of government. ...

Contents

History

Noise barriers have been built intuitively, but infrequently, in the United States since the mid twentieth century, when vehicular traffic burgeoned; however, in the late 1960s acoustical science technology emerged to mathematically evaluate the efficacy of a noise barrier design adjacent to a specific roadway. Below, a researcher collects data to calibrate a roadway noise model for Foothill Expressway. Acoustics is a branch of physics and is the study of sound (mechanical waves in gases, liquids, and solids). ... This page is related to transport; you may be looking for the 2002 Bollywood movie Road. ... Roadway noise is the most prevalent form of environmental noise. ...

Acoustical scientist measures sound in Noise barrier design study, Santa Clara County, Calif.
Acoustical scientist measures sound in Noise barrier design study, Santa Clara County, Calif.

The best of these early computer models considered the effects of roadway geometry, topography, vehicle volumes, vehicle speeds, truck mix, roadway surface type and micrometeorology. Several research groups within the U.S. developed variations of the computer modelling techniques: Caltrans Headquarters in Sacramento, California; the ESL inc. group in Palo Alto, California; the Bolt, Beranek and Newman[1] group in Cambridge, Massachusetts and a research team at the University of Florida. Possibly the earliest published work that scientifically designed a specific noise barrier was the study for the Foothill Expressway in Los Altos, California[2]. Image File history File links Metadata Size of this preview: 800 × 402 pixelsFull resolution (1856 × 932 pixel, file size: 491 KB, MIME type: image/jpeg) i took this pic and release all rights I, the creator of this work, hereby release it into the public domain. ... Image File history File links Metadata Size of this preview: 800 × 402 pixelsFull resolution (1856 × 932 pixel, file size: 491 KB, MIME type: image/jpeg) i took this pic and release all rights I, the creator of this work, hereby release it into the public domain. ... This article or section does not cite any references or sources. ... Santa Clara County is a county located in Californias San Francisco Bay Area. ... Calabi-Yau manifold Geometry (Greek γεωμετρία; geo = earth, metria = measure) is a part of mathematics concerned with questions of size, shape, and relative position of figures and with properties of space. ... For discussion of land surfaces themselves, see Terrain. ... The Trikke is a Human Powered Vehicle (HPV) This article is about the means of transport. ... Satellite image of Hurricane Hugo with a polar low visible at the top of the image. ... Caltrans logo The soaring ramps in the stack interchanges favored by Caltrans often provide stunning views. ... Location of Sacramento in Sacramento County, California County Sacramento Government  - Mayor Heather Fargo Area  - City  99. ... Location of Palo Alto within Santa Clara County, California. ... BBN Technologies (originally Bolt Beranek and Newman) is a high technology company that provides research and development services. ... Location in Massachusetts Coordinates: , Country United States State Massachusetts County Middlesex County Settled 1630 Incorporated 1636 Government  - Type Mayor-council city  - Mayor Kenneth Reeves (D) Area  - City  7. ... The University of Florida (commonly referred to as Florida or UF) is a public land-grant, space-grant, research university located in Gainesville, Florida. ... Los Altos (IPA: ) is a city at the southern end of the San Francisco Peninsula, in the San Francisco Bay Area. ...


Rapidly following, there ensued numerous case studies across the U.S. addressing dozens of different existing and planned highways. These studies were commonly commissioned by State Highway Departments and were mostly conducted by one of the four research groups mentioned above. The U.S. National Environmental Policy Act[3] had arrived and effectively mandated the quantitative analysis of noise pollution from every Federal-Aid Highway Act Project in the U.S., propelling noise barrier model development and application. With passage of the Noise Control Act of 1972[4], demand for noise barrier design soared from a host of noise regulation spinoff. The National Environmental Policy Act (or, NEPA) was signed into law on January 1, 1970 by US President Richard Nixon. ... Noise pollution (or environmental noise in technical venues) is displeasing human or machine created sound that disrupts the environment. ... The following bills in the United States have been known as the Federal-Aid Highway Act: Federal-Aid Highway Act of 1938 Federal-Aid Highway Act of 1944 Federal-Aid Highway Act of 1948 Federal-Aid Highway Act of 1950 Federal-Aid Highway Act of 1952 Federal-Aid Highway Act... The Noise Pollution and Abatement Act of 1972 (or Noise Control Act of 1972, 92-574, 86 Stat. ... Noise regulation includes statutes or guidelines relating to sound transmission established by national, state or provincial and municipal levels of government. ...


By the late 1970s there were over a dozen research groups in the U.S. applying similar computer modelling technology and addressing at least 200 different locations a year for noise barriers. As of 2006, this technology is considered a standard in the evaluation of noise pollution from highways, but, remarkably, the nature and accuracy of the computer models used is nearly identical to the original 1970 versions of the technology. A computer simulation or a computer model is a computer program which attempts to simulate an abstract model of a particular system. ... 2006 is a common year starting on Sunday of the Gregorian calendar. ... Noise pollution (or environmental noise in technical venues) is displeasing human or machine created sound that disrupts the environment. ... A computer simulation or a computer model is a computer program which attempts to simulate an abstract model of a particular system. ...


Theory of noise barrier design

Noise barrier earth berm along Highway 12, Sonoma County, California
Noise barrier earth berm along Highway 12, Sonoma County, California

The acoustical science of noise barrier design is a complex task based upon treating a roadway or railway as a line source. Firstly, the theory is based upon blockage of sound ray travel toward a particular receptor; however, diffraction of sound must be addressed. That is to say, sound waves bend (downward) when they pass an edge, such as the apex of a noise barrier. Further complicating matters is the phenomenon of refraction, the bending of sound rays in the presence of an inhomogeneous atmosphere. Wind shear and thermocline produce such inhomogeneities. Image File history File links Metadata Size of this preview: 800 × 386 pixelsFull resolution (1840 × 888 pixel, file size: 245 KB, MIME type: image/jpeg) i, razorback, took this picture and relaese all rights I, the creator of this work, hereby release it into the public domain. ... Image File history File links Metadata Size of this preview: 800 × 386 pixelsFull resolution (1840 × 888 pixel, file size: 245 KB, MIME type: image/jpeg) i, razorback, took this picture and relaese all rights I, the creator of this work, hereby release it into the public domain. ... Route 12 or Highway 12 can refer to: Alberta provincial highway 12 British Columbia provincial highway 12 Manitoba Provincial Highway 12 Nova Scotia Route 12 Highway 12 (Ontario) Prince Edward Island Route 12 Saskatchewan Highway 12 Interstate 12 U.S. Route 12 Arkansas Highway 12 State Route 12 (California) Delaware... Sonoma County is a county located on Californias Pacific coast north of the San Francisco Bay Area. ... North-South Expressway in Malaysia; a roadway can be considered as a line source of air and noise pollution and need not be a straight line. ... Look up Receptor in Wiktionary, the free dictionary. ... The intensity pattern formed on a screen by diffraction from a square aperture Diffraction refers to various phenomena associated with wave propagation, such as the bending, spreading and interference of waves passing by an object or aperture that disrupts the wave. ... This article is about compression waves. ... The straw seems to be broken, due to refraction of light as it emerges into the air. ... View of Jupiters active atmosphere, including the Great Red Spot. ... It has been suggested that this article or section be merged with wind gradient. ... The thermocline is a layer within a body of water where the temperature changes rapidly with depth. ...


The sound sources modelled must include engine noise, tire noise and aerodynamic noise, all of which factors vary by vehicle type and speed. One can begin to visualize the complexity of the resulting computer model, which is based upon dozens of physics equations translated into thousands of lines of computer code. An engine is something that produces an effect from a given input. ... For a table of tire companies, see List of tire companies. ... Aerodynamics is a branch of fluid dynamics concerned with the study of gas flows, first analysed by George Cayley in the 1800s. ... A computer simulation or a computer model is a computer program which attempts to simulate an abstract model of a particular system. ... This article is about equations in mathematics. ...


Some noise barriers consist of a masonry wall or earthwork, or a combination thereof, such as a wall atop an earth berm. Sound abatement walls are commonly constructed using steel, concrete, masonry, wood, plastics, insulating wool, or composites. In the most extreme cases, the entire roadway is surrounded by a noise abatement structure, or dug into a tunnel using the cut-and-cover method. The noise barrier may either be constructed on private land or on a public right-of-way or other public land or other surface such as a marsh, public or private. Since sound levels are measured using a logarithmic scale, a reduction of nine decibels is equivalent to elimination of about 80 percent of the unwanted sound. The bottom line is that noise barriers can be extremely effective tools for noise pollution abatement, although theory also calculates that certain locations and topographies are not suitable for use of any reasonable noise barrier. Clearly cost and aesthetics play a role in the final choice of any noise barrier. Look up Berm in Wiktionary, the free dictionary. ... An underground pedestrian tunnel between buildings at MIT. Note the utility pipes running along the ceiling. ... A right-of-way (plural: rights-of-way) is an easement or strip of land granted to a railroad company upon which to build a railroad. ... A logarithmic scale is a scale of measurement that uses the logarithm of a physical quantity instead of the quantity itself. ... The decibel (dB) is a logarithmic unit of measurement that expresses the magnitude of a physical quantity (usually power) relative to a specified or implied reference level. ... Noise pollution (or environmental noise in technical venues) is displeasing human or machine created sound that disrupts the environment. ... The Parthenons facade showing an interpretation of golden rectangles in its proportions. ...


Tradeoffs in noise barrier design

This noise abatement wall in The Netherlands has a transparent section at the driver's eye-level to reduce the visual impact.
This noise abatement wall in The Netherlands has a transparent section at the driver's eye-level to reduce the visual impact.

There are clear disadvantages of noise barriers, most prominently: Image File history File links Metadata Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 278 KB, MIME type: image/jpeg) (All user names refer to nl. ... Image File history File links Metadata Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 278 KB, MIME type: image/jpeg) (All user names refer to nl. ...

  • Aesthetic impacts for motorists and neighbors, particularly if scenic vistas are blocked.
  • Considerable costs of design, construction and maintenance.
  • Necessity to design custom drainage that the barrier may interrupt.

Normally the benefits of noise reduction far outweigh aesthetic impacts for residents protected from unwanted sound. These benefits include lessened sleep disturbance, improved ability to enjoy outdoor life, reduced speech interference, stress reduction, reduced risk of hearing impairment and reduction in blood pressure (improved cardiovascular health). A sleep disorder (somnipathy) is a disorder in the sleep patterns of a person or animal. ... In medical terms, stress is the disruption of homeostasis through physical or psychological stimuli. ... Hearing impairment is a full or partial decrease in the ability to detect or understand sounds. ... A sphygmomanometer, a device used for measuring blood pressure. ... The circulatory system or cardiovascular system is the organ system which circulates blood around the body of most animals. ...


With regard to construction costs, a major factor is the availability of excess soil in the immediate area which could be used for berm construction. If the soil is present, it is often cheaper to construct an earth berm noise barrier than to haul away the excess dirt, provided there is sufficient land area available for berm construction. Generally a four to one ratio of berm cross sectional width to height is required. Thus, for example, to build a six foot high berm, one needs an available width of 24 feet. Look up Berm in Wiktionary, the free dictionary. ...


Earth berm noise barriers can be constructed solely of excess earth from grading pads for a residential development it will protect. Thus its entire construction cost is negligible; arguably, it may pay into the project, since offhaul of earth may have been needed. A further nuance of this particular project is that the residential side of the berm is overexcavated, which gives more privacy between highway and homes and also enhances noise benefit. Finally, note the aesthetics of the earth berm which blends with scenic elements of the natural hills of Annadel State Park in the background. It may be a surprise to find out this berm is over six feet in height, since the aesthetics of earth mounding reduce the visual impact of the structure, compared to a soundwall. Aesthetics (or esthetics) (from the Greek word αισθητική) is a branch of philosophy dealing with the nature of beauty. ... Annadel State Park, Sonoma County, California, USA is situated at the northern edge of Sonoma Valley and offers many recreational activities within its 5,000 acre (2,000 ha) property. ...


As a minor embellishment to noise barrier design, one may note the concept of constructing a louver or cap atop the wall that is directed back toward the noise source. This concept follows the theory that such a design should inhibit shadow zone diffraction filling in sound behind the noise barrier. In actual experience the benefits are slight compared to the benefits of a higher barrier and the costly construction techniques necessary to create and maintain such a device. Variation of the louver design can be found in Denmark, where the designs are also intended to minimize reflected sound. Furthermore some of the Danish soundwalls are made of transparent materials to minimize the visual impact; such material use, however, compromises the efficacy by reducing mass.


References

  1. ^ John Shadely, Acoustical analysis of the New Jersey Turnpike widening project between Raritan and East Brunswick, Bolt Beranek and Newman, 1973
  2. ^ C.M. Hogan and Harry Seidman, Design of Noise Abatement Structures along Foothill Expressway, Los Altos, California, Santa Clara County Department of Public Works, ESL Inc., Sunnyvale, California, October, 1970
  3. ^ * U.S. National Environmental Policy Act, enacted January 1, 1970
  4. ^ Public Law No. 92-574, 86 Stat. 1234 (1972)Noise Pollution and Abatement Act of 1972, codification amended at 42 U.S.C. 4901-4918 (1988)

The New Jersey Turnpike is a toll road in New Jersey and is one of the most heavily traveled highways in the United States. ... Los Altos (IPA: ) is a city at the southern end of the San Francisco Peninsula, in the San Francisco Bay Area. ... Santa Clara County is a county located in Californias San Francisco Bay Area. ... ESL Incorporated is a high technology U.S. firm engaged in software design, systems analysis and hardware development for the strategic reconnaisance marketplace. ... Location of Sunnyvale within Santa Clara County, California. ... The National Environmental Policy Act (or, NEPA) was signed into law on January 1, 1970 by US President Richard Nixon. ...

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