The effects of site selected variables on human responses to traffic noise,Part II: Road type by socio-economic status by traffic noise level

The results of the second part of a field study of human response to traffic noise are reported. The influence of traffic noise level, socio-economic status, and road type (freeway or conventional road) were investigated in a controlled manner determined by subject selection procedures. Human response measures were obtained from interviewer administered questionnaires, and were as spatially and temporally coincident with the noise measurements as possible. Noise measurements were obtained from six days of rapidly sampled digital recordings. Although traffic noise level was the major predictor of the intensity of negative responses, other site variables produced significant effects. Parallel variations in the day-night difference in sound levels appeared to contribute to these effects. Spontaneous responses supported the validity of the elicited responses. Freeway noise was found to produce a more continuously disturbing noise environment and was concluded to be a more pervasive form of disturbing environmental noise.     

The effects of site selected variables on human responses to traffic noise,part III: Community size by socio-economic status by traffic noise level

This paper reports the results of the third part of a field study of human responses to traffic noise. The influence of traffic noise level, community size, and socio-economic status were investigated in a controlled manner determined by subject selection procedures. Human responses were obtained from interviewer administered questionnaires, and were as spatially and temporally coincident with the noise measurements as possible. Noise measurements were obtained from several days of rapidly sampled digital recordings. Traffic noise level was the major predictor of the intensity of elicited responses. A number of other significant effects were observed largely related to community size. These were explained as due to parallel variations in the perceived necessity of vehicles, the annoyance with aircraft noise, and the logarithm of the vehicle flow rate. The results did demonstrate effects related to community size, and thus it is unwise to extrapolate the results of large city noise studies to small communities and rural areas.     

Motorway noise modelling based on perpendicular propagation analysis of traffic noise

A model for motorway traffic noise has been obtained from measurements along the the Bangkok-Chonburi motorway. The model’s parameters include traffic volume and combination, the average spot speed of each type of vehicle and the physical conditions of the motorway in terms of right-of-way width, number of lanes, lane width, shoulder width, and median width for both of the main carriageways and frontage roads. The noise level that is generated by each type of vehicle has been analyzed according to the propagation in the direction perpendicular to the center line of motorway’s carriageway. The total traffic noise is then analyzed from traffic volume of all vehicle types on both sides of carriageways and frontage roads. The basic noise levels used in the motorway traffic noise model are modified according to the effective ground effect along the propagation path. The final result of this study is that a motorway traffic noise model based on the perpendicular propagation analysis technique performs well in a statistical goodness-of-fit test against the field data, and therefore, can be used effectively in traffic noise prediction for related or similar motorway projects.     

The effects of long-term exposure to railway and road traffic noise on subjective sleep disturbance

The exposure-response relationships between subjective annoyance with sleep disturbance from railway trains and road traffic noise were established from an extensive social survey by CENVR (Center for Environmental Noise and Vibration Research) in Korea. The objectives of this research are to determine the long-term effects of noise on sleep and to compare the exposure-response relationships from different noise sources with those from other studies and to elucidate the effects of some modifying factors on subjective responses to noise. From an investigation of the percentage of a highly sleep-disturbed population (%HSD) in response to railway and road traffic noise, it was found that sleep is affected more by railway noise than by road traffic noise. The effects of non-acoustical factors on the responses were examined and sensitivity was shown to be a significant modifying factor, as it pertains to subjective sleep disturbance. A comparison of the response curves from an analysis of pooled data from predominantly European surveys by Miedema and Vos [Behav. Sleep Med. 5, 1-20 (2007)] with the response curves from this survey showed more of a subjective sleep disturbance response in this survey to railway noise, whereas there was no significant difference in terms of a response to road traffic noise.     

公路交通噪声阈限值的分析研究

本文采用客观测量和主观评价相结合的方法研究公路交通噪声对人的影响。通过研究，求得了公路交通噪声扰民的容忍阈值，分析了比较了公路交通噪声各种客观评价量与人的主观评价量的之间的相互关系。     

A field study of effects of road traffic and railway noise on polysomnographic sleep parameters

The aim of this study was to explore and compare the effect of noise from railway and road traffic on sleep in subjects habitually exposed to nocturnal noise. Forty young and middle aged healthy subjects were studied with polysomnography (PSG) during two consecutive nights in their own bedroom. Noise measurements and recordings were conducted concurrently outside of the bedroom fac?ade as well as inside the bedroom of each participant. Different noise exposure parameters were calculated (L(p,A,eq,night), L(p,A,Fmax,night), and L(AF5,night)) and analyzed in relation to whole-night sleep parameters. The group exposed to railway noise had significantly less Rapid eye movement, (REM) sleep than the group exposed to road traffic noise. A significant association was found between the maximum level (L(p,A,Fmax,night)) of railway noise and time spent in REM sleep. REM sleep was significantly shorter in the group exposed to at least a single railway noise event above 50 dB inside the bedroom. These results, obtained in an ecological valid setting, support previous laboratory findings that railway noise has a stronger impact than road traffic noise on physiological parameters during sleep, and that the maximum noise level is an important predictor of noise effects on sleep assessed by PSG, at least for railway noise.     

Development of a highway traffic noise prediction model that considers various road surface types

A highway traffic noise prediction model has been developed for environmental assessment in South Korea. The model is based on an outdoor sound propagation method and is fully compliant with ISO 9613 and the sound power level (PWL) estimation for a road segment, as suggested in the ASJ Model-1998 that is based on PWLs. Due to that model’s selection of two pavement types, such as asphalt or concrete pavement, an unacceptable traffic noise prediction is made in cases where the road surface is different from that on which the model is based. In order to address this problem, several road surface types are categorized, and the PWL of each surface type is determined and modeled by measuring the noise levels obtained from newly developed methods. An evaluation of the traffic noise prediction model using field measurements finds good agreement between predicted and measured noise levels.     

A simple formula for evaluating the acoustic effect of balconies in protecting dwellings against road traffic noise

This study explores the noise reducing effect of a balcony and describes the development of a simple theory pertaining to the propagation of traffic noise from a road into a balcony. A new methodology is proposed that is based on the well-known prediction scheme—“Calculation of Road Traffic Noise” (CRTN)—developed in the UK. A geometrical ray theory is developed for the prediction of noise levels inside a balcony due to road traffic. The source level of road traffic noise is obtained as per the standard CRTN methodology. However, road sub-segmentations and new approaches for the prediction of noise levels at illuminated and shadow zones inside a balcony are proposed. Field measurements have been conducted on four different types of balcony to validate the proposed methodology. The insertion loss, defined as the difference in the noise levels with and without the presence of a balcony, has been used to assess the shielding effectiveness of a balcony against road traffic noise. The simple theory is validated by outdoor field measurements. It is also found that a properly designed balcony can provide considerable screening effects in protecting dwellings against road traffic noise.     

Subjective response to noise in rural villages,particularly from road traffic

Subjective response to noise, particularly from road traffic, arising from 10 villages in rural Hampshire and Wiltshire is compared with response from a previous survey carried out on a representative sample of adults resident in England. This English sample consisted of individuals occupying, for the most part, urban and suburban areas. The background (ambient) levels of noise experienced were, on the whole, lower in the rural study; especially at sites exposed to most traffic. There was no evidence of a difference in dose/response relationships between the two studies with respect to road traffic noise.     

The effect of road traffic noise on house prices

Existing U.K. legislation compensates home owners for house price depreciation due to increases in environmental noise caused by public works. Several previous studies have been attempted to show the effects of noise on house prices but have been inconclusive because of a failure to meet basic requirements for a rigorous analysis. In this paper these requirements are discussed and a study designed to fulfil them based on the southern Ontario housing market is described. Data on 2277 individual housing transactions at 51 sites close to major roadways were analyzed to determine the effects of road traffic noise on house prices. Results show that noise has a significant and consistent effect equal to approximately $254 per decibel depreciation at the arterial sites examined and $312 per decibel depreciation at the expressway sites.     

New vehicle noise emission for French traffic noise prediction

Traffic noise prediction models in France are based on vehicle noise emission values defined by the French Guide du Bruit des Transports Terrestres (Noise Guide for Ground Transport - Noise levels prediction). These emission values are suited for models addressing the noise assessments of road infrastructures and the dimensioning of acoustic protections, needing traffic noise estimations in terms of ?_Aeq over a long period of time (an hour or more).The values, obtained from measurements collected in the 70s, are updated in the publication of a new guide (Methodological Guide, Vehicle noise emissions, to be published), which addresses the road surface influence on tyre/road noise. The emission values are now expressed through the contributions of a power unit component, function of traffic speed, traffic flow type and road declivity, and of a rolling noise component, function of traffic speed and road pavement.The paper outlines the procedures followed to determine the components, gives their numerical values, and illustrates some vehicle noise emissions.     

Characteristics of road traffic noise in Hanoi and Ho Chi Minh City, Vietnam

Noise pollution due to road traffic is a major global concern because of its negative impact on the quality of life in communities everywhere. In Vietnam, traffic noise has become an increasingly noticeable and serious problem in large cities like Hanoi and Ho Chi Minh City. To gain more insight into the characteristics of this noise, intensive noise measurements were conducted in Hanoi and Ho Chi Minh City in September 2005 and September 2007, respectively. A comprehensive dataset of noise was obtained that included 24-h noise measurements as well as short-term noise recordings. The volume of traffic was also quantified by reproducing video camera recordings. Noise datasets from both cities were then compared with a dataset of Japanese traffic noise obtained in Kumamoto. The results showed that the traffic noise in Hanoi and Ho Chi Minh City was characterized by relatively high noise exposure levels due to the large number of motorbikes and frequent horn sounds. The sound of horns contributed a definite impact of 0-4 dB on noise exposure in Hanoi and Ho Chi Minh City, where noise levels decreased with the absence of horn sounds. Our results also showed differences in the characteristic traffic noise of Vietnam and Japan.     

Long term sleep disturbance due to traffic noise

This contribution to the evaluation of the effects of traffic noise on sleep disturbance is focused on the responses of people living near a main road. Experiments were carried out in the homes of subjects who had habitually been exposed to noise for periods of more than four years. The chronic changes in overall sleep patterns and the temporary sleep responses to particular noise events caused by traffic are demonstrated. Young people show mainly stage 3 and 4 deficits whilst older people show REM sleep deficits. The cardiac response to noise during sleep was also examined. These results highlight that both long term average and peak levels are important in assessing sleep disturbance. The threshold levels, measured inside the bedroom and above which sleep quality starts to become impaired, are 37 L_eq(A) and 45 dB (A)L_{p max}, respectively. For the type of traffic studied these two levels are coherent and it is therefore possible that a single noise index, L_eq(A), is sufficient to scale sleep disturbance.     

Patterns of behaviour in dwellings exposed to road traffic noise

An inquiry involving a total of 1500 subjects residing in 15 different sites in the conurbations of Lyon and Marseilles was carried out in 1979 with a view to determining the behaviour and attitudes of people with regard to traffic noise. The main purpose of the inquiry was to identify the objective reactions to the traffic noise and to determine how such reactions varied with the noise level, with account taken of the socio-economic characteristics of the subjects (age, income, owner occupier or tenant, etc.). The 08.00–20.00 hour L_eq noise level was measured or calculated for each of the dwellings included in the inquiry. The 00.00–05.00 and 20.00–24.00 hour L_eq values were also derived for each case and a total of nearly 20 000 different noise levels were involved in the analysis of the data for this inquiry. On considering the completed questionaires it was found that the annoyance experienced during the day was more closely correlated with the noise level (r = 0·64) than had been the case with the results of previous studies. In addition to showing how traffic noise can interfere with activities and lead, for example, to the closing of windows to shut out the noise, the inquiry yielded information on the way in which activities affected by noise are transferred to quieter rooms, on the extent to which individual dwellings are sound proofed, on the extent to which occupants are likely to move to another dwelling in order to escape from the noise and finally on some aspects of the effects of noise on health and sleep. Thus it appears that a daytime L_eq value of more than 65 dB(A) gives rise to what can be regarded as forced behavioural responses to the extent that there are significant changes in the normal way of life of the people concerned and such responses give an indication of the magnitude of the social costs that can be attributed to the undesirable effects of traffic noise.     

Road traffic noise exposure in residential complexes built at different times between 1950 and 2000 in Hong Kong

This paper attempts to determine the exposure of the urban population to road traffic noise living in residential complexes built at different times between 1950 and 2000 in Hong Kong. Noise exposure was estimated at the residents’ dwelling, neighborhood and community by noise mapping. The purpose of the study is to find out if the noise exposure levels of these residential complexes have improved as a result of stepped up noise control and reduction efforts. A total of 212 residential complexes built at different times, by the government and private sector in different districts, were selected for noise assessment. The results show that, compared to private housing, public housing estates are generally exposed to less road traffic noise. The study has also found that, over the 50-year period, the dwelling noise exposure levels of the recently built residential complexes are lower than the older ones, showing some improvement over time. This is particularly more noticeable at the high exposure end. There is however only some small differences in noise level between recent and old developments at the community scale both for public and private housing estates.     

利用自相关函数和双耳自相关函数分析对交通噪声特征参量的提取~

对实地双通道测量获得的道路交通噪声和铁路噪声信号样本进行了自相关函数和双耳自相关函数(Interaural CrossCorrelation Function)的分析。进而通过对噪声样本时间因子和空间因子的相关性分析、主成分分析和主观评价实验,得到了3个铁路噪声源特征参量物理因子和4个道路交通噪声源特征参量物理因子。发现与传统的声压级测量相比,表征声音信号时间特性和空间特性的这7个物理量可以更全面、准确地表征交通噪声的特性。在对道路噪声进行测量或分析时,掌握与声源视觉宽度和音调感相对应的物理因子以及双耳时延和初始能量,就可获悉与人的主观评价相一致的道路交通噪声特征信息;对铁路噪声而言,掌握与声源视觉宽度相对应的物理因子以及双耳时延和声音的重复性特征,就可以得到与入主观评价相一致的铁路噪声特征信息。综合道路噪声特征参量和铁路噪声特征参量可以发现,双耳时延和与声源视觉宽度相对应的物理因子是与人的主观反应最为一致的主成分指标,说明噪声中决定人的评价的最主要的因素是代表空间特征的信号因子。      

The contribution of heavy vehicles to urban traffic noise

The dominating influence of road traffic on the noise climate of the world's cities is now established and attempts to reduce the problem follow two main lines: The first involves ameliorating the effects of traffic stream noise; the second an attack on the noise levels of individual vehicles. The great expense involved in developing and building quieter vehicles justifies expending considerable effort in establishing the relative noise contribution of the vehicle types found in typical urban traffic mixtures. This paper describes the development of a field method for examining the effects of heavy vehicles such as trucks and buses on the noise profile of the traffic stream. The essential feature of the method involves synchronisation of a recorded voice commentary with the traffic noise. The graphical record of this noise can then be annotated to show what type of vehicles cause the peaks in the overall noise profile.     

Effects of urban morphology on the traffic noise distribution through noise mapping: A comparative study between UK and China

Due to the rapid urban development and massive population increase in many eastern cities, the difference in urban density and morphology between typical western and eastern cities is becoming significant. This consequently makes the noise distribution in the eastern cities rather different from typical low density European cities. In this research, two representative cities with different urban densities, Greater Manchester in the UK and Wuhan in China, were selected, which have low and high average urban density respectively, and also have considerable differences in building form and traffic pattern. In the mean time, these two cities have similar urban scale and traffic amount. In each city, based on the urban morphological analyses considering urban land-use, building and road density, and noise source distribution, a number of typical urban areas, 500 * 500 m² each, were sampled. A noise-mapping software package was then used to generate generic noise maps, based on existing digital vector maps for terrain and building, and traffic data obtained by on-site measurements. The comparison results show that the average and minimum noise level in Greater Manchester samples is generally higher than that in Wuhan samples, while the maximum noise level in Wuhan samples is mostly higher. By developing a Matlab program, correlations have been analysed between noise distributions and the urban characteristics relating to urban density, such as the road and building coverage ratio. Overall, comparisons between these two typical cities have shown significant effects of urban morphology on the traffic noise distribution.     

An experimental and theoretical study of the modelling of road traffic noise and its transmission in the urban environment

This paper describes experiments conducted on the modelling of traffic noise using a $\text{1}\text{80th}$ scale model of a subdivision of a city. The emphasis in this study was on the correct evaluation of ground absorption effects. There were essentially four phases to the study. First, the applicability of various scaling law regimes was examined. It was shown that $\text{1}\text{80th}$ scaling using air as a transmission medium was at least a practical choice. The second phase concerned itself with the choice of materials for the model, particularly that which was to simulate the ground. An impedance measuring apparatus was developed and used to test materials. The third part of the work concerned itself with the development of an anechoic enclosure and a sound source to simulate traffic noise; modulated Hartmann whistles were used for this purpose. Finally, a model of part of a residential area of Calgary was built and sound transmission measurements obtained. These results were compared with field measurements. It was shown that good agreement existed between the field and model measurements.     

A traffic noise prediction method based on vehicle composition using genetic algorithms

The effect of traffic composition on the noise pollution has been investigated in a small city Erzurum, located in eastern Turkey, where the population is about 400,000. Manual noise measurements and vehicle counts were performed at the four heaviest traffic points in the city for a period of 12 h. Using the information on vehicle composition and the maximum legal noise emissions of each type of vehicles, two prediction models based on genetic algorithms have been developed that can be used as tools for in-city traffic flow redesign. The models have been validated against some of the noise data. Measured traffic noise levels have been compared with predictions using the new models and some existing ones and a relatively good agreement has been obtained between them.