Highway Traffic Noise Research Articles

Reduction of equivalent continuous A-weighted sound pressure levels by porous elastic road surfaces

A porous elastic road surface (PERS) is superior to drainage asphalt pavement for reducing highway traffic noise. In earlier research and development, for example using a test track, the difference in sound power level (Lw) of cars has been regarded as the noise reduction effect since it was not possible to measure the change in equivalent continuous A-weighted sound pressure level (Leq) for a series of vehicles on such a limited length of surface. As the result of a comparatively major test construction on a highway, have measured the noise reduction effect of PERS as the difference in Leq. First, we measured the motor vehicle Lw and Leq on each section. However, we found that the neighbouring paved sections also influenced Leq. Next, we calculated Leq according to a highway traffic noise model, using the values of Lw measured in the different paved sections. Since the calculated Leq corresponded approximately with the measured Leq, we could verify the validity of the measured Lw. We again calculated Leq, assuming that each pavement is infinitely long. We assumed the improvement of noise reduction effect of PERS was indicated through the calculated Leq. Consequently, we have found that the noise reduction effect of drainage asphalt pavement was 5–6 dB, whereas that of PERS was 7–9 dB.

GIS-based highway traffic noise analysis for land use planning

Improved accessibility caused by the development of roads is a major driving force for faster economic growth of a country. However, the uncontrolled roadside development and exposure to adverse environmental impacts in the absence of proper land use planning is often a major concern to planners. Traditional land use planning is not directly governed by environmental considerations. In the present paper a GIS based approach is suggested for the analysis of noise level due to highway development projects. The use of modelled noise levels for land use planning in the surrounding areas of highways is also demonstrated with reference to a case study in India.

Highway traffic noise prediction using method fully compliant with ISO 9613: comparison with measurements

In this study, we introduce outdoor sound simulation that is fully compliant with ISO 9613 yet with some complementary methods that enhance its applicability; for example, calculation of sound attenuation due to undulating terrain in octave bands, geometric divergence in the near-field of the source, and short-term wind effects. Using the method, we have carried out highway traffic noise prediction and measurement for 12 sites with representative road shapes and structures. In the prediction, the sound power level for a road segment was estimated by the method suggested in ASJ Model-1998 with experimental corrections to the overall noise level and spectrum. Comparing results between predicted and measured noise levels show good correspondence at direct, diffracted and reflected sound fields within 30m from the center of the near side lane.

루이빌대 개별State-specific 데이터를 이용한 도로 교통소음 수준 비교 - 오픈공간에서 -

루이빌대 개별State-specific 데이터를 이용한 도로 교통소음 수준 비교 - 오픈공간에서 -

Porous Elastic Road Surface as Urban Highway Noise Measure

Highway traffic noise is a serious problem in urban areas of Japan, not only for residents along highways but also for highway administrators. Only 13% of urban highways have met the environmental standard for noise. Noise barriers cannot be used as a noise countermeasure on most highways for which access is not controlled. This problem is impeding new highway construction in urban areas. Since 1993 the Public Works Research Institute (PWRI) has been developing a new low-noise pavement called porous elastic road surface (PERS). This new pavement has a porous structure composed of granulate rubber made from used tires as its aggregate and urethane resin as its binder. It is estimated that the potential noise reduction levels in the Leq sound level exceed 10 dB (A). More than 90% of highways in urban areas would meet the standard if this noise reduction level were achieved. The general performance of PERS obtained through past development at the PWRI is examined. Results of recent research done to improve the noise reduction levels of PERS further and the first test construction using PERS in Japan are summarized. The noise measurement result at the site indicates that PERS has enough potential to solve highway traffic noise problems in urban areas of Japan.

Highway traffic noise barriers in the U.S. - Construction trends and cost analysis

Highway traffic noise barriers in the U.S. - Construction trends and cost analysis

Characterization of highway traffic noise generated by rigid pavement contraction joints

Contraction joints in rigid (concrete) pavements are required to permit expansion of each monolithic section of roadway. At higher speeds, the major source of highway noise is attributed to vehicle tire/roadway interaction. Current concerns about limiting the impact of highway traffic noise has forced transportation agencies to consider strategies to control noise generated by tire/roadway interaction. Within this work the difference in noise generated by 1/4‐ vs 3/8‐in. joint widths is conducted. The study focuses on passenger vehicles including a sedan and a light duty van/truck. Both vehicle in‐cabin and roadside noise levels are measured for vehicle speeds of 50, 60, and 70 miles per hour. For the sedan, the minimum and maximum observed in‐cabin differences were determined to be 1.08 and 1.82 dB(A), respectively. Minimum and maximum observed roadside differences are 1.19 and 2.58 dB(A), respectively. Van tests resulted in minimum and maximum observed in‐cabin differences of 0.60 and 1.09 dB(A) and minimum and maximum observed roadside differences of 1.05 and 3.18 dB(A), respectively. This paper contains details of reference standards, test methods, and the results obtained.

고속도로 교통소음 예측-자동차 주행소음의 음향파워레벨 평가

고속도로 교통소음 예측-자동차 주행소음의 음향파워레벨 평가

Noise prediction for highways in Thailand

A model of highway traffic noise is formulated based on vehicle types. The data were collected from local highways in Thailand with free-flow traffic conditions. First, data on vehicle noise was collected from individual vehicles using sound level meters placed at a reference distance. Simultaneously, measurements were made of vehicles’ spot speeds. Secondly, are data for building the highway traffic noise model. This consists of traffic noise levels, traffic volumes by vehicle classification, average spot speeds by vehicle type, and the geometric dimension of highway sections. The free-flow traffic noise model is generated from this database. A reference energy mean emission level (the basic noise) level for each type of vehicles is developed based on direct measurement of Leq (10 s) from the real running condition of each type of vehicles. Modification of terms and parameters are used to make the model fit highway traffic characteristics and different types of vehicle.

고속도로 교통소음 예측-전달감쇠 산정

This paper presents some advanced and supplemental methods to enhance the accuracy In case of calculating geometric divergence attenuation, attenuation by multiple screening structures, ground attenuation at unflat surfaces of sound during propagation outdoors by the methods specified in ISO 9613-2. Moreover, a calculation method for considering short-term wind effect, specified in ASJ Model-1998, is also introduced. To verity the accuracy of adopted methods, we have carried out highway traffic noise prediction and measurement at tile twelve locations appearing representative road shapes and structures, such as flat, retained cut, elevated, barrier-constructed roads. From the results, we have confirmed the predicted results show good correspondence with the measured at direct, diffracted and reflected sound fields within 30 m from the center of near side lane.

Highway traffic noise measurements compared to predictions from FHWA’s Traffic Noise Model

In 1998, the United States Federal Highway Administration (FHWA) released a new tool for highway traffic noise prediction and noise barrier design, the Traffic Noise Model (TNM). In order to assess the accuracy and make recommendations on the use of TNM for the FHWA, the Volpe Center Acoustics Facility performed numerous roadside measurements, obtaining over 100 h of traffic noise data from highways around the country. For each site, acoustical, meteorological, and traffic data were collected simultaneously throughout the measurement period. Spectrum analyzers were used to collect 1/3-octave band A-weighted equivalent sound levels, and the microphones were deployed at distances from 50 to 1300 ft from the roadway and at two heights off the ground, the number of microphones used being site dependent. In comparing the measured and TNM-predicted sound levels, results indicate that TNM is, on average, within 1 dB of the measured data for all types of sites combined. Grouping the data by site types shows how well TNM is performing for open (no barrier), acoustically soft ground sites; open, acoustically hard ground sites; and sites with noise barriers.

Geotechnical and environmental considerations in highway layouts: an integrated GIS assessment approach

Highway route layout design typically relies on aerial photographs, topographic maps and geologic maps. In this paper, a GIS platform, which incorporates the main digital data needed for evaluating route layouts, is used in a computer-based approach for highway layout assessment. Possible layouts are evaluated based on two sets of criteria. First, traditional evaluation criteria focussing on geometric design factors and impact on man-made features are considered. Next, the developed assessment framework builds on the GIS platform to generate specific environmental and geotechnical criteria for route layout evaluation. The developed approach integrates highway design, slope stability, and traffic noise modeling packages and specifically written codes with the GIS packages ARC/INFO and ArcView. A prototypical application of the assessment framework for a proposed highway south of the city of Beirut, Lebanon is presented. The results demonstrate the potential of the developed approach in incorporating new evaluation criteria at the route layout design stage and in automating the route layout assessment procedure.

A spatial analysis of topographic and vegetation factors affecting the propagation of highway traffic noise

This paper presents the results of a spatial analysis of measured noise levels with environmental factors derived from a geographic information system (GIS). The more traditional methods used by the Federal Highway Administration (FHWA, 1978 and 1982) are range limited and not suitable for large-scale topographic variation near a freeway noise source. Over 30 field measurements of noise levels were collected along a freeway in San Diego County that included a heterogeneous landscape of mesas and valleys. A digital elevation model and a vegetation map of the study area have been incorporated into a GIS to evaluate a suite of environmental factors. Topographic features limit the line-of-sight analysis traditionally used in the past and new variables of landscape ‘‘ensonification’’ and slope configuration are shown to bridge part of that gap in this study.

Rain and hail simulation and sound isolation tests on a wood and metal roof assembly

A series of acoustic tests were performed on a proposed roof construction for a new concert hall at The University of North Texas to evaluate its sound transmission loss properties. The test was conducted to determine if the wood and metal deck construction would be sufficient to isolate nearby highway traffic noise (airborne) and heavy rain and hail noise (structure-borne) from being heard in the concert hall. Four variations of the roof system were constructed and tested to determine the range of possible solutions. Simulation of rain and hail noise test methods and results are presented along with standard ASTM E-90 results and the recommended solution.

Highway Noise Barriers: 1994 Survey of Practice

Highway traffic noise is an ever-increasing problem for transportation agencies. The challenge presented to transportation agencies is to incorporate noise abatement into the highway environment without compromising the aesthetic integrity of the surrounding communities. In an effort to guide highway designers, a survey of practice was sent to all state transportation agencies and their equivalents in Puerto Rico and Ontario, Canada. The portions of the survey regarding noise-barrier materials, aesthetic visual quality in design, and public involvement in the design process are discussed in this paper. The literature review revealed a long-standing effort throughout Europe to incorporate many aesthetic features into noise-barrier systems and to use public preferences to guide design. Many new products that provide aesthetically pleasing noise barriers, in addition to the noise-level reductions required of transportation agencies, are now available. Innovative and versatile methods of using standard materials, such as concrete, have provided a continual supply of barrier designs. A multidisciplinary collaboration (including citizen representatives) in the design process has proved to be an effective method of ensuring that the best design is implemented for both sides of the highway environment. Collectively, transportation agencies, private industry, and institutional research programs should work together to advance the knowledge available in noise research and to further develop the aesthetic visual quality of the highway environment.

Highway Noise Barriers: 1994 Survey of Practice

Highway traffic noise is an ever-increasing problem for transportation agencies. The challenge presented to transportation agencies is to incorporate noise abatement into the highway environment without compromising the aesthetic integrity of the surrounding communities. In an effort to guide highway designers, a survey of practice was sent to all state transportation agencies and their equivalents in Puerto Rico and Ontario, Canada. The portions of the survey regarding noise-barrier materials, aesthetic visual quality in design, and public involvement in the design process are discussed in this paper. The literature review revealed a long-standing effort throughout Europe to incorporate many aesthetic features into noise-barrier systems and to use public preferences to guide design. Many new products that provide aesthetically pleasing noise barriers, in addition to the noise-level reductions required of transportation agencies, are now available. Innovative and versatile methods of using standard materials, such as concrete, have provided a continual supply of barrier designs. A multidisciplinary collaboration (including citizen representatives) in the design process has proved to be an effective method of ensuring that the best design is implemented for both sides of the highway environment. Collectively, transportation agencies, private industry, and institutional research programs should work together to advance the knowledge available in noise research and to further develop the aesthetic visual quality of the highway environment.

Using the STAMINA 2.0 computer program to calculate contours of one-hour-average sound levels from highway traffic noise

Using the STAMINA 2.0 computer program to calculate contours of one-hour-average sound levels from highway traffic noise

Effectiveness of grass embankments in screening high-rise buildings from highway traffic noise

There is a common perception among residents of high-rise buildings facing an expressway that by having a grass embankment in front of the buildings the traffic noise is reduced to some extent. This study shows that the grass embankment would benefit only those living at lower levels, say below the fifth storey. For those living on the tenth storey and above, the traffic noise is about the same regardless of whether the intervening ground is flat or sloped. As traffic noise increases as one goes up a building, therefore, in the practical sense, a grass embankment would hot help reduce the traffic noise for high-rise buildings. Also, it is not possible in tropical Singapore to seal windows facing an expressway. Air-conditioning the apartments is too costly, and as most of these high-rise buildings are for the lower-income group, paying for air-conditioning is beyond the occupants' means. Building of noise barriers (which would need to be several kilometres long) along the expressways is not only costly, but also unsightly, and with a barrier height of say 4 m the line of sight for residents living on the fifteenth storey and above is not cut off. Therefore, the only viable way of achieving a desirable traffic noise level is for the buildings to be set further from the kerb of the expressway.

Use of Vegetation for Abatement of Highway Traffic Noise

The high cost of conventional highway noise abatement methodology (i.e., free‐standing walls) has made mitigation of many impacted sites economically infeasible. A solution that may prove more economically reasonable for those sites is the use of strategically planted evergreen vegetation to form a dense barrier between the highway and impacted area. Field measurements were made on vegetative barriers planted only for visual screening purposes. The results of these measurements indicate that a 2 to 3 dB decrease in noise levels is possible with a narrow [30 ft (9.1 m)] belt of vegetation. These measurements are supported by the literature review, which indicates that an even further reduction may be possible with a barrier planted and maintained in such a way as to encourage maximum density growth. When coupled with the non‐quantifiable psychological effects of blocking the highway from view, and the low construction cost, the potential for solving uneconomical abatement problems is clear.

Highway traffic noise prediction with and without barriers—Some results and observations

Although the past decade has been a time of rapid increase in sophistication of models for predicting highway traffic noise levels including the effects of barriers, several important questions remain unanswered. This paper describes some barrier and near‐ground propagation modeling work recently completed and nearing completion at Penn State, and discusses questions arising therefrom. A point of view looking towards the needs of the utlimate users of traffic noise prediction models is attempted. Experiences in both indoor and outdoor barrier testing and with both controlled sources and free‐flowing traffic sources will be drawn upon in the presentation.