Simulation Approach to Traffic Noise Modeling: American Automobile Manufacturers Association Community Noise Model Version 4.0

1997 ◽  
Vol 1601 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Roger L. Wayson ◽  
John M. MacDonald ◽  
Ronald Eaglin ◽  
Barbara Wendling
Keyword(s):  
Simulation Model ◽  
Traffic Noise ◽  
The United States ◽  
Point Sources ◽  
Noise Model ◽  
Community Noise ◽  
Model Free ◽  
Sound Levels ◽  
Acceleration And Deceleration ◽  
Interrupted Flow

Several models are available for predicting traffic noise levels. The FHWA-promulgated model, STAMINA 2.0, is the most widely used noise model in the United States and is used to model free-flow vehicular traffic. STAMINA 2.0 cannot directly model interrupted-flow traffic. Sound levels from interrupted-flow traffic can be approximated with STAMINA 2.0 using the method presented in NCHRP Report 311. This method is time-consuming and difficult to use. These limitations demonstrate the need for a traffic noise model that can model the acceleration and deceleration behavior of interrupted-flow traffic. The University of Central Florida has developed the American Automobile Manufacturers Association Community Noise Model (CNM). The CNM is a traffic simulation model that determines sound levels at receivers by modeling vehicles as discrete moving point sources. The vehicle energy is determined from acceleration, deceleration, idle, and cruise reference energy mean emission level curves. Sound energy attenuation is calculated from distance, ground absorption, and user input barriers. The model sums the energy at receivers from all vehicles and then calculates the Leq noise level at the receivers. It is demonstrated that the CNM predicts receiver Leq levels that are very close to STAMINA 2.0 results for constant-speed traffic. The CNM can also accurately predict sound levels at receivers located before and after intersections. In addition to the advantages of a real simulation model, the CNM is user friendly, allowing the user to place lanes and receivers using the mouse.

Acoustic Modeling of Meteorological Effects on Roadway Noise

2021 ◽  
pp. 036119812199458
Author(s):  
Roger L. Wayson ◽  
Kenneth Kaliski
Keyword(s):  
Road Traffic ◽  
Traffic Noise ◽  
Model Development ◽  
The United States ◽  
Noise Model ◽  
Road Traffic Noise ◽  
Atmospheric Conditions ◽  
Noise Propagation ◽  
Transportation Research ◽  
Meteorological Effects

Modeling road traffic noise levels without including the effects of meteorology may lead to substantial errors. In the United States, the required model is the Traffic Noise Model which does not include meteorology effects caused by refraction. In response, the Transportation Research Board sponsored NCHRP 25-52, Meteorological Effects on Roadway Noise, to collect highway noise data under different meteorological conditions, document the meteorological effects on roadway noise propagation under different atmospheric conditions, develop best practices, and provide guidance on how to: (a) quantify meteorological effects on roadway noise propagation; and (b) explain those effects to the public. The completed project at 16 barrier and no-barrier measurement positions adjacent to Interstate 17 (I-17) in Phoenix, Arizona provided the database which has enabled substantial developments in modeling. This report provides more recent information on the model development that can be directly applied by the noise analyst to include meteorological effects from simple look-up tables to more precise use of statistical equations.

Traffic Noise Model vs. Extreme Topography

2003 ◽  
Vol 1859 (1) ◽  
pp. 65-71
Author(s):  
Michael A. Staiano
Keyword(s):  
Traffic Noise ◽  
Severe Case ◽  
Sound Attenuation ◽  
Noise Model ◽  
Interstate Highway ◽  
Site Model ◽  
Sound Levels

Traffic noise exposures were measured at various locations adjacent to an Interstate highway and compared with sound levels predicted by the FHWA Traffic Noise Model (TNM). The prediction procedure underestimated the measured sound attenuation by 6 to 12 A-weighted decibels. Various TNM site model configurations were evaluated in an effort to improve agreement between measurements and predictions. For the site tested—a severe case with relatively distant receptors and extreme topography—variations in ground impedance (including a median ground zone) had little benefit or were counterproductive, while adding topographic detail via terrain lines helped somewhat. The best agreement resulted from the incorporation of a tree zone for the wooded site. However, this benefit is thought to be chance, because the site was not only relatively lightly wooded but also thinly foliaged at the time of the on-site measurements.

Florida Noise Barrier Evaluation and Computer Model Validation

2003 ◽  
Vol 1859 (1) ◽  
pp. 72-78 ◽  
Author(s):  
Roger Wayson ◽  
John MacDonald ◽  
Ahmed EI-Assar ◽  
Win Lindeman ◽  
Mariano Berrios
Keyword(s):  
Insertion Loss ◽  
Traffic Noise ◽  
Sound Level ◽  
Noise Model ◽  
Barrier Method ◽  
Noise Barriers ◽  
Zone Length ◽  
Sound Levels ◽  
Noise Barrier ◽  
Source Level

The results of a project that investigated the effectiveness of in situ noise barriers in Florida are presented. The prediction accuracy of the FHWA Traffic Noise Model (TNM) is compared with STAMINA 2.0 and 2.1 (Florida-specific). A total of 20 barrier sites were visited during a 3-year period that resulted in 844 discrete 20-min equivalent sound level (Leq) measurements behind the barriers. Barrier insertion loss was determined using the ANSI indirect barrier method. A methodology was developed to estimate shadow zone length created behind highway noise barriers. All of the barriers tested were effective (>5 dB:LAeq insertion loss at distances equivalent to the first row of homes, where LAeq is the A-weighted Leq) except one site because of marginal additional shielding from a berm–barrier combination. Only three sites had an insertion loss of less than 5 dB at distances representative of the second row of homes. Overall, measurements indicate that the barriers provide substantial sound level reduction for residents along the highway. TNM was the best prediction model when considering all test sites; however, the STAMINA models were more accurate at predicting source level. TNM predictions using the Average pavement input overpredicted the reference sound levels measured at these sites. TNM predictions using the OGAC (open-graded asphalt concrete) input were improved (under 2 dB:LAeq of error) over those using the Average pavement type input. This result is expected because Florida uses an open-graded asphalt friction mix.

Anti-noise model-free adaptive control and its application in the circulating fluidized bed boiler

2020 ◽  
pp. 095965182097937
Author(s):  
Na Dong ◽  
Wenjin Lv ◽  
Shuo Zhu ◽  
Donghui Li
Keyword(s):  
Adaptive Control ◽  
Complete Convergence ◽  
Circulating Fluidized Bed ◽  
Control Method ◽  
Noise Model ◽  
Good Resistance ◽  
Industrial Systems ◽  
Noise Interference ◽  
Model Free ◽  
Tracking Differentiator

Model-free adaptive control has been developed greatly since it was proposed. Up to now, model-free adaptive control theory has become mature and tends to be an effective solution for complex unmodeled industrial systems. In practical industrial processes, most control systems are inevitably accompanied by noise that will result in indelible error and may further cause inaccurate feedback to the output. In order to solve this kind of problem with model-free technique, this article incorporates an improved tracking differentiator into model-free adaptive control. After that, the anti-noise model-free adaptive control method with complete convergence analysis is proposed. Meanwhile, numerical simulation proves that the improved control method can quickly track a given signal with good resistance to noise interference. Finally, the effectiveness and practicability of the proposed algorithm are verified by experiments through the control of drum water level of circulating fluidized.

Nitrate in aquifers beneath agricultural systems

2002 ◽  
Vol 45 (9) ◽  
pp. 19-29 ◽  
Author(s):  
M.R. Burkart ◽  
J.D. Stoner
Keyword(s):  
United States ◽  
Groundwater Vulnerability ◽  
The United States ◽  
Point Sources ◽  
Nitrate Contamination ◽  
Agricultural System ◽  
Agricultural Systems ◽  
Fertilizer Use ◽  
Unconfined Aquifers ◽  
The World

Research from several regions of the world provides spatially anecdotal evidence to hypothesize which hydrologic and agricultural factors contribute to groundwater vulnerability to nitrate contamination. Analysis of nationally consistent measurements from the U.S. Geological Survey’s NAWQA program confirms these hypotheses for a substantial range of agricultural systems. Shallow unconfined aquifers are most susceptible to nitrate contamination associated with agricultural systems. Alluvial and other unconsolidated aquifers are the most vulnerable and shallow carbonate aquifers provide a substantial but smaller contamination risk. Where any of these aquifers are overlain by permeable soils the risk of contamination is larger. Irrigated systems can compound this vulnerability by increasing leaching facilitated by additional recharge and additional nutrient applications. The agricultural system of corn, soybeans, and hogs produced significantly larger concentrations of groundwater nitrate than all other agricultural systems, although mean nitrate concentrations in counties with dairy, poultry, cattle and grains, and horticulture systems were similar. If trends in the relation between increased fertilizer use and groundwater nitrate in the United States are repeated in other regions of the world, Asia may experience increasing problems because of recent increases in fertilizer use. Groundwater monitoring in Western and Eastern Europe as well as Russia over the next decade may provide data to determine if the trend in increased nitrate contamination can be reversed. If the concentrated livestock trend in the United States is global, it may be accompanied by increasing nitrogen contamination in groundwater. Concentrated livestock provide both point sources in the confinement area and intense non-point sources as fields close to facilities are used for manure disposal. Regions where irrigated cropland is expanding, such as in Asia, may experience the greatest impact of this practice.

scholarly journals Automotive traffic noise and urban public spaces

2021 ◽  
Vol 9 (72) ◽  
Author(s):  
Greicikelly Gaburro Paneto ◽  
Cristina Engel de Alvarez ◽  
Paulo Henrique Trombetta Zannin
Keyword(s):  
Urban Space ◽  
Sound Pressure ◽  
Traffic Noise ◽  
Motor Vehicles ◽  
Open Spaces ◽  
Sound Levels ◽  
Measurement Results ◽  
Sound Pressure Levels ◽  
High Sound

In contemporary cities, and usually without realizing it, the population has been exposed to high sound pressure levels, which besides causing discomfort, can lead to health problems. Considering that a large part of this noise comes from emission from motor vehicles, this research aims to evaluate the sound behavior in sound environments configured by voids in the urban fabric, in order to identify whether open spaces can act as attenuators of sound levels. To obtain the expected results, the methodology used was structured from a review of the state-of-the-art and computer simulations relating the variables that influence the formation of urban space and sound emission and propagation, taking as a case study an urban portion of the municipality of Vitória/ES. In parallel, questionnaires were applied to evaluate the user's perception of their exposure. The measurement results indicated that the sound pressure levels caused by traffic noise are above the limit tolerated limit by the NBR norm 10151:2000 for the daytime period. In turn, the results obtained from the population indicated that there is little perception of noise by the users of the spaces surveyed.

scholarly journals Wintertime Arctic Air Pollution over central Alaska: pre-ALPACA campaign

2021 ◽  
Author(s):  
Eleftherios Ioannidis ◽  
Kathy S. Law ◽  
Jean-Christophe Raut ◽  
Tatsuo Onishi ◽  
Louis Marelle ◽  
...  
Keyword(s):  
Air Pollution ◽  
The United States ◽  
Point Sources ◽  
The Arctic ◽  
Formation Mechanisms ◽  
Winter Conditions ◽  
Local Point ◽  
Temperature Inversions ◽  
Local Emissions ◽  
Pollution Episodes

<p>The wintertime Arctic is influenced by air pollution transported from mid-latitudes, leading to formation of Arctic Haze, as well as local emissions such as combustion for heating and power production in very cold winter conditions. This contributes to severe air pollution episodes, with enhanced aerosol concentrations, inter-dispersed with cleaner periods. However, the formation of secondary aerosol particles (sulphate, organics, nitrate) in cold/dark wintertime Arctic conditions, which could contribute to these pollution episodes, is poorly understood.</p><p>In this study, which contributes to the Air Pollution in the Arctic: Climate, Environment and Societies - Alaskan Layered Pollution and Arctic Chemical Analysis (PACES-ALPACA) initiative, the Weather Research Forecasting Model with chemistry (WRF-Chem) is used to investigate wintertime pollution over central Alaska focusing on the Fairbanks region, during the pre-ALPACA campaign in winter 2019-2020. Fairbanks is the most polluted city in the United States during wintertime, due to high local emissions and the occurrence of strong surface temperature inversions trapping pollutants near the surface.</p><p>Firstly, different WRF meteorological and surface schemes were tested over Alaska with a particular focus on improving simulations of the wintertime boundary layer structure including temperature inversions. An optimal WRF set-up, with increased vertical resolution below 2km, was selected based on evaluation against available data.</p><p>Secondly, a quasi-hemispheric WRF-Chem simulation, using the improved WRF setup, was used to assess large-scale synoptic conditions and to evaluate background aerosols originating from remote anthropogenic and natural sources affecting central Alaska during the campaign. The model was run with Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants (ECLIPSE) v6b anthropogenic emissions and improved sea-spray aerosol emissions. Discrepancies in modelled aerosols compared available data are being investigated (e.g. missing dark formation mechanisms, treatment of removal processes).</p><p>Thirdly, fine resolution simulations, using high resolution emissions (e.g. 2019 CAMS inventory), including local point sources, over the Fairbanks region, were used to investigate chemical and dynamical processes influencing aerosols under different meteorological conditions observed during the field campaign including a cold stable episode and a period with possible mixing of air masses from aloft. The model was evaluated against available aerosol, oxidant (ozone) and aerosol precursor data from surface monitoring sites and collected during the pre-campaign, including vertical profile data collected in the lowest 20m. The sensitivity of modelled aerosols to meteorological factors, such as relative humidity, temperature gradients and vertical mixing under winter conditions are investigated.</p>

scholarly journals METHODUCAL APPROACH AND ASSESSMENT OF NOISE IMPACT OF RAIL TRANSPORT ON THE BASIS OF THE USE OF RISK ASSESSMENT METHODOLOGY

2019 ◽  
Vol 96 (7) ◽  
pp. 675-681 ◽  
Author(s):  
Olga I. Kopytenkova ◽  
D. E. Kurepin ◽  
K. B. Fridman ◽  
E. B. Kuznetsova
Keyword(s):  
Extreme Values ◽  
Residential Buildings ◽  
Traffic Noise ◽  
Calculated Data ◽  
Ground Surface ◽  
Field Measurements ◽  
Railway Transport ◽  
Sound Levels ◽  
Age Related ◽  
Zone Of Influence

The paper presents the results of measurement, prediction and assessment of noise in the territory in the zone of the influence of the railway transport. The railway transport is established to be a source of excess acoustic impact on the environment within the area of sanitary break (100 m). The dependence of the change in noise levels from freight trains at a distance of 100 m from the source and up to 30 m from the ground surface was revealed. Equivalent sound levels in octave bands for the railway section of the model are calculated. Based on the results of field measurements and calculated data, the identification of indices of risk for adverse reactions in the population living in the zone of influence of the Railways was executed. The paper presents results of the calculation of the probability of occurrence of complaints on excessive noise and the likelihood of irritation at the noise, and the results of the calculation of risk indices of pathologies of the nervous and cardiovascular systems. The research made it possible to identify the regulatory documentation discrepancy in the definition of the health gap between the line source traffic noise and residential buildings. Field measurements and executed on their basis their modeling of the noise propagation (without obstacles) have shown that on the boundary of the regulatory sanitary protection zone (100m) in the congested section of the railway the noise level of 60-62 dBA is maintained. The risk of irritation to the noise and the likelihood of complaints is assessed as “acceptable”. The risk of pathology of the cardiovascular system is evaluated as “low”. At a distance of 50 m (65 dBA) with bearing in mind age-related changes after 70 years of exposure the risk reaches of extreme values - 0,935. Construction sites located less than 100 m from the railway were shown to fall into the zone of acoustic discomfort. There was substantiated the necessity of resolving differences in regulatory documentation by harmonizing sanitary and technical groups documents regulating methods of measurement, prediction and evaluation of sound levels on the territories in the zone of influence of the Railways.

Community noise from urban air mobility (UAM) and its control by traffic management

2021 ◽  
Vol 263 (6) ◽  
pp. 187-193
Author(s):  
Michael Bauer
Keyword(s):  
Traffic Management ◽  
Electric Propulsion ◽  
Traffic Noise ◽  
Environmentally Friendly ◽  
Urban Air ◽  
Acoustic Characteristics ◽  
Operational Conditions ◽  
Community Noise ◽  
Open Questions ◽  
Noise Metrics

The awareness about UAM is amplified by steadily growing numbers of air taxi concepts being announced. In general environmentally friendly by electric propulsion, community noise and en-route noise are still prominent open questions. Several studies for larger UAM aircraft, describing the acoustic characteristics of a variety of potential air taxi concepts, have been performed by the author. Due to the abovementioned multitude of different vehicle concepts and their multiple operational conditions, each of them shows individual sound characteristics. Therefore, further investigations of noise created by air taxi fleets appear to be crucial. Understanding of community noise around vertiports and along air taxi routes will strongly depend on those fleets. In this paper, acoustically different air taxi systems are composing different sets of air taxi fleets, used for air traffic noise simulations. The simulations start with baseline scenarios of equally represented taxi systems on fixed flight paths with several flight levels in a certain air lane. The final fleets are consisting of random air taxi composition with randomly populated flight paths. The results, based on common noise metrics and changes in the number of affected residents, could provide a first indication how to reduce community noise by future UAM traffic management.

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