Appraisal of Urban Road Traffic Noise in tier-II City (Surat City), India

Urban road traffic noise pollution has always been identified as a severe problem that affects urban populants. In developing nation, road traffic noise pollution depends on the composition of heterogeneous traffic composition. These traffic compositions contain vehicles, which have different sizes, speeds variations, a different dimension of vehicles. Environmental noise measurements have been carried out during day-time and night-time in different locations of tier-II city of India. The noise levels have been continuously measured over 24 h periods using kimo DB 300 class-2 noise level meter. The data contained in this research paper represent 768 measurement hours. All the information has been used to investigate the time patterns of the noise levels under a wide range of different conditions and to study the relationships between noise levels and traffic in urban areas. Maximum L_Aeq was observed 73.3 dB(A) at B₁₄ location and the minimum was recorded 65.7 dB(A) at C₃ location, which was greater than the central pollution control board (CPCB) prescribed limits during night time. A major reason for the generation of road traffic noise is due to the equal composition of 2-wheeler and 4-wheeler on the arterial road and heavy vehicles were recorded during morning peak and evening peak even though they are prohibited during peak hours.     

A multiple regression model for urban traffic noise in Hong Kong

This article describes the roadside traffic noise surveys conducted in heavily built-up urban areas in Hong Kong. Noise measurements were carried out along 18 major roads in 1999. The measurement data included L10, L50, L90, Leq, Lmax, the number of light vehicles, the number of heavy vehicles, the total traffic flow, and the average speed of vehicles. Statistical analysis using the analysis of variance (ANOVA) and Tukey test (p<0.05) reveals that the total traffic flow and the number of heavy vehicles are the most significant factors of urban traffic noise. Multiple regression was used to derive a set of empirical formulas for predicting L10 noise level due to road traffic. The accuracy of these empirical formulas is quantified and compared to that of another widely used prediction model in Hong Kong--the Calculation of Road Traffic Noise. The applicability of the selected multiple regression model is validated by the noise measurements performed in the winter of 2000.     

Estimating traffic noise for inclined roads with freely flowing traffic

Traffic noise measurements on the kerbs of 19 independent inclined trunk roads with freely flowing traffic within the residential areas of Hong Kong are carried out in the present investigation. The performance of the existing noise prediction models in predicting traffic noise from inclined roads is evaluated. By regression analysis and simple physical consideration of the traffic noise production mechanisms, formulae for the prediction of the L_A10, L_A50, L_A90 and L_Aeq are developed or re-calibrated. Results suggest tyre noise has the major contribution to the overall noise environment when the source is an inclined trunk road. Also, the road gradient is found to have a higher contribution to the traffic noise than assumed in the existing models, but becomes unimportant when the background noise level L_A90 is concerned.     

A novel traffic-noise prediction method for non-straight roads

In view of the well-recognized need for the availability of simple traffic noise–prediction methods for non-straight roads, such as interchanges and flyovers, an approximate traffic noise–prediction model, suitable for non-straight roads, was developed following the modeling process of the Federal Highway Administration’s (FHWA) traffic-noise model. The approximate model is simpler than the FHWA model when the non-straight road is divided into several road sections, their traffic-noise levels calculated individually, and all the sound levels superimposed to obtain the total traffic-noise level of the entire non-straight road. The rational length of the small road section was investigated. The traffic-noise levels predicted using the approximate and the FHWA models were compared through an example and were shown to differ only very marginally. The approximate model is thus suitable for traffic-noise prediction for non-straight roads.     

Testing the acoustical corrections for reflections on a façade

The assessment of noise levels, in the proximity of a building or on its façade, is a requirement of the European Environmental Noise Directive 2002/49/EC concerning environmental noise produced by road and railway traffic, airports and industries. The corrected values for the noise levels and the problems of measuring noise near a façade are discussed here for the case of road traffic. A complete set of measurements in different situations was performed along several roads in an urban environment as well as in a controlled situation using a loudspeaker. The experimental results are then compared against theoretical models and international standards, in particular those that suggest to use a +3 or +6 dB correction as a function of the microphone position and the NordTest method. Some suggestions are given for the different corrective factors to apply when measuring environmental noise between 0 and 2 m away from a building façade, and practical solutions identified.     

Prediction and Limitations of Noise Maps Developed for Heterogeneous Urban Road Traffic Condition: A Case Study of Surat City,India

Road traffic noise pollution has been recognized as a serious issue which affects human health as well as affects urban regions. Noise maps are very beneficial to identify the impact of noise pollution. A noise mapping study performed to study the propagation of noise in tier-II city along with field measurements. The noise maps are developed using a computer simulation model (SoundPLAN essential 4.0 software). The noise prediction models like U.K’s CoRTN, Germany’s RLS-90, and their modified versions, which can be used for homogenous road traffic conditions, cannot be successfully applied in heterogeneous road traffic conditions of India. In developing country like India, road traffic noise pollution depends on the composition of heterogeneous traffic volume, variance in road geometrical, honking conditions, un-authorized parking, and varying density of the building on either side of the road. These traffic compositions contain vehicles, which have different sizes, speeds variations, a different dimension of vehicles. Because of fluctuating speeds, lack of lane disciplines, and un-authorized parking on main road lanes, honking events becomes inevitable, which changes and affects the urban soundscape of nations like India. Analysis of noise maps showed that horn honking due to un-authorized parked vehicles contributed an additional increase up to 11 dB (A) noise, which is quite significant.     

信号灯控制下的主道双车道入匝道系统交通流特性研究

采用元胞自动机模型研究了具有信号灯控制的主道为双车道的入匝道系统交通流特性.将信号灯设置在入匝道口处,通过信号灯来引导主道和匝道上的车辆通行.分析了信号灯控制对主道与匝道的车流量、系统通行能力以及入匝道口处的车流平均速度的影响.通过相图比较,说明信号灯控制的双车道入匝道系统能模拟出比信号灯控制的单车道入匝道系统更加符合实际的交通流特性.与姜锐提出的模型［Jiang R 2003 J. Phys. A 36 11713］结果相比,信号灯控制下的匝道系统的交通流状态得到改善并且道路通行能力有所提 关键词： 交通流 元胞自动机 入匝道系统 信号灯     

Comparison of dose-response relationships between railway and road traffic noises: the moderating effect of distance

It has been found in European studies that railway noise causes less annoyance than road traffic noise. However, recent Japanese studies have shown that there is no systematic difference in dose-response relationships between railway and road traffic noises. In general Japanese houses are situated closer to railways or roads than European houses. The purpose of the study was to investigate whether the distance from noise source to houses influences community responses to railway and road traffic noises. A re-analysis was made of data from social surveys on community responses to railway and road traffic noises, which have been obtained from 1994 to 2001 in Kyushu, a warmer area of Japan and Hokkaido, a colder area. The results showed that the annoyance in areas close to railways was greater than that in distant areas, while there was no difference in dose-response relationships for road traffic noise between both areas. Considering the situation of houses in Europe and Japan, it is expected that the annoyance caused by railway noise is more severe in Japan than in Europe. The distance from noise source to houses may be one of the causes of the difference in community responses between Europe and Japan.     

Honking noise corrections for traffic noise prediction models in heterogeneous traffic conditions like India

In developing countries like India, the nature of the composition of traffic is heterogeneous. A heterogeneous traffic flow consists of vehicles that have different sizes, speeds, vehicle spacing and operating characteristics. As a result of the widely varying speeds, vehicular dimensions, lack of lane disciplines, honking becomes inevitable. In addition, it changes the urban soundscape of developing countries. In heterogeneous traffic conditions, horn events increase noise level (L_den) by 0.5–13 dB(A) as compared to homogenous traffic conditions. Therefore, the traffic prediction models that are used for homogenous traffic conditions are not applicable in heterogeneous traffic conditions. To increase the accuracy of noise prediction models, in depth understanding of heterogeneous traffic noise is required. Understanding the real traffic noise characteristics requires quantification of some of the basic traffic flow characteristics such as speed, flow, Level Of Service (LOS) and density. In a given roadway, the noise level changes with density and LOS on the road. In this paper, a new factor for horn correction is introduced with respect of Level Of Service (LOS). The horn correction values can be incorporated in traffic noise models such as CRTN, FHWA, and RLS 90, while evaluating heterogeneous traffic conditions.     

Towards a model for electric vehicle noise emission in the European prediction method CNOSSOS-EU

The CNOSSOS-EU method is recommended in Europe for environmental noise prediction. In regards to road traffic, it includes vehicle noise emission models implicitly referring to internal combustion vehicles. The development of electrically driven vehicles calls for the future consideration of these vehicles in prediction models. On the basis of experimental data, the study reported in this paper proposes a noise emission model for extending CNOSSOS-EU to light electric vehicles. Correction terms to be applied to the propulsion noise component are determined. Investigations on a sample of tyres with good rolling resistance performance, which is a main tyre selection criterion on these vehicles, indicated that no correction is required for the rolling noise component. Differences between the noise emission from conventional vehicles and electric vehicles are discussed for several road surfaces. Owing to the limited vehicle sample as well as transitional statements, this new model for electric vehicles running at constant speed over 20 km/h should be considered as a first step towards the definition of this vehicle technology in CNOSSOS-EU.     

城市道路交通噪声烦恼度社会调查

本文以烦恼度为主观反应指标,采用三种5级程度衡量尺度,对西安市内三条主要干道和两类典型交叉口附近区域内的道路交通噪声进行了烦恼度问卷调查。此次调查针对人口统计学因素(性别、年龄、文化程度、身体健康状况)上的个体差异与等级描述词不同的程度尺度可能对道路交通噪声烦恼度调查结果的影响,以及特定路况条件下的噪声烦恼度与不同机动车辆的行驶噪声烦恼度展开了研究。通过对调查数据的分析处理,发现并初步总结出:与选取不同的烦恼度尺度相比,人口统计学因素对调查结果的影响更加显著;人口统计学因素与特定路况条件下的噪声烦恼度及不同机动车辆的行驶噪声烦恼度无明显相关;但不同机动车辆的行驶噪声烦恼度不同,实际研究中需对摩托车噪声加以重视并区别对待。     

Community responses to road traffic noise in Hanoi and Ho Chi Minh City

Vietnam is a developing country in southeast Asia, and its environment has been seriously affected by industrialization and urbanization. In large cities like Hanoi (northern Vietnam) and Ho Chi Minh City (southern Vietnam), noise emission from road traffic has been found to be a serious concern among general public. In 2005 and 2007, two large-scale socio-acoustic surveys of community response to road traffic noise were conducted to investigate human reactions to road traffic noise in these cities; the sample sizes were 1503 people in Hanoi and 1471 in Ho Chi Minh City. The noise exposure levels (L_den) were 70–83 dB in Hanoi and 75–83 dB in Ho Chi Minh City. Noise annoyance was estimated using standardized annoyance scales. For both cities, dose–response relationships were established between L_den and the percentage of highly annoyed respondents. Compared to annoyance responses of European people, Vietnamese were less annoyed by road traffic noise by about 5 dB. Hanoi respondents seemed to be more annoyed by noise than Ho Chi Minh City respondents. Conversation and sleep disturbances were not as serious as expected in either city. Furthermore, window orientation in the home was found to affect activity disturbances.     

Evaluation and analysis of the environmental noise of Messina, Italy

In this paper, the results of a study on the environmental noise pollution of the city of Messina (Italy) are presented. The investigation has included a preliminary classification of the territory in six acoustically homogeneous areas according to Italian noise regulations. On the basis of the resultant acoustic zoning 35 sites were selected for an experimental survey. This last has been carried out by extensive measurements of the main indexes for noise pollution (L_eq, L₁, L₁₀, L₅₀, L₉₀, L₉₉) and of the traffic flow and composition. Results indicate that: (a) main roads of Messina are overloaded by traffic flow during day-time period and that in all the examined sites daily average sound levels due to road traffic exceed environmental standards by about 10 dBA; (b) environmental noise exhibits a certain degree of spatial variance resulting primarily from the peculiar geo-morphological structure of the town and from the transport infrastructure and (c) more than 25% of residents should be highly disturbed by road traffic noise.     

Noise prediction for urban traffic conditions—related to measurements in the Sydney Metropolitan Area

A method for the prediction of the noise levels from road traffic, developed at the National Physical Laboratory (NPL), has been used for comparison with measured values of road traffic noise in the Sydney Metropolitan Area. As the comparison was not good, multiple regression analysis, using the basic format of the NPL formula, was performed. A better comparison was obtained from a formula in which the term relating to the average road speed of the vehicles was excluded. This new formula permits a simple graphical representation for the determination of $\text{L}{}_{\mathrm{<mtext>10</mtext>}}$ for urban traffic. A similar formula and graph for the determination of $\text{L}{}_{\mathrm{<mtext>eq</mtext>}}$ is also provided.     

Influence of expanding ring roads on traffic noise in Beijing City

The road network in Beijing is expanding in the form of loop-lines. Following the 2nd and 3rd ring roads, the 4th has been completed and come into operation in 2002. Traffic noise surveying and analysis was performed along four main roads in the Beijing urban area—the 2nd, 3rd and 4th ring roads circling the central downtown area and Chang-An Avenue, a major east-west corridor through the heart of the city. Measured noise data along the 2nd, 3rd and Chang-An Avenue were compared with the data surveyed before the completion of the 4th ring road for determining influence of expanding ring roads on traffic noise pattern in Beijing City. The results indicate that these main roads remain overloaded by traffic flow during daytime, and noise levels due to road traffic along these roads exceeds relavent environmental standards by 5 dBA. Reduced traffic noise level was observed along the northern half of the 2nd and 3rd ring roads, and along the central section of Chang-An Avenue. Increased traffic noise level was observed along the southern half of the 2nd and 3rd ring roads, and along the non-central section of Chang-An Avenue. Expanding ring roads mitigate heavy traffic flow in the central part of Beijing City, but spread high traffic noise outwards at the same time.     

Variability in road traffic noise levels

Environmental noise levels can vary over a wide range as a result of the diversity of site conditions and activities occurring during field measurements. This variability, extremely important for a correct measurement interpretation, is often a source of disagreement when applying standards and regulations, as there is no consensus about how to estimate and present it. The paper contributes to this technical debate by investigating the statistical variability associated with a large measurement database acquired under field conditions. The database consists of 2 week’s noise recordings at each of 50 separate locations in residential areas affected mainly by road traffic noise. The results show increased variability (standard deviations) at the lower values of either logarithmic or arithmetic mean L_Aeq over the time periods investigated. It is anticipated that the observed relationships may be of assistance when estimating the noise level variability and the uncertainty associated with a noise measurement affected by road traffic or other environmental noise sources.     

A road traffic noise pattern simulation model that includes distributions of vehicle sound power levels

Annoyance, sleep disturbance and other health effects of road traffic noise exposure may be related to both level and number of noise events caused by traffic, not just to energy equivalent measures of exposure. Dynamic traffic noise prediction models that include instantaneous vehicle noise emissions can be used to estimate either of these measures. However, current state-of-the-art vehicle noise emission models typically consider a single emission law for each vehicle category, whereas measurements show that the variation in noise emission between vehicles within the same category can be considerable. It is essential that the influence of vehicles that are producing significantly more (or less) noise than the average vehicle are taken into account in modeling in order to correctly predict the levels and frequency of occurrence of road traffic noise events, and in particular to calculate indicators that characterize these noise events. Here, an approach for predicting instantaneous sound levels caused by road traffic is presented, which takes into account measured distributions of sound power levels produced by individual vehicles. For the setting of a receiver adjacent to a dual-lane road carrying free flow traffic, the effect of this approach on estimated percentile levels and sound event indicators is investigated.     

Developing a Durable Quiet Road Surface

Road traffic noise can have a significant impact on the quality of life for residents close to major road networks. One of the most effective measures for reducing the noise from road traffic, particularly on high-speed roads, is to ensure the use of a low noise road surface. Research on pavement construction and the measurement of its acoustic properties has shown that significant noise reductions can be achieved through the use of certain road surface types. However certain low noise road surfaces do not exhibit the desired durability associated with more traditional pavements, leading to costly and disruptive maintenance regimes.
This article looks at the mechanisms involved in tyre/road noise generation and how these interact with various road surface properties including a brief overview of some common surface types. It then goes on to explain how these concepts informed the development of an asphalt surfacing material with enhanced durability and good acoustic performance without compromising safety. Progress in testing the resulting Premium Asphalt Surfacing System (PASS) is outlined, including the completion of a successful network trial.     

Community reactions to noise from freely flowing traffic,motorway traffic and congested traffic flow

Responses to a social survey were collected from residents of 27 different sites in the Greater Manchester area. The sites were exposed to noise emanating from (a) freely flowing traffic on urban roads, or (b) motorway traffic, or (c) congested or disturbed traffic flow on urban roads. Existing noise indices were tested on this general sample of traffic flow situations to determine their efficacy in the prediction of community dissatisfaction to traffic noise. No existing index could handle adequately all the traffic flow conditions. When the indices were combined with measures of traffic volume flow between midnight and 6 a.m. a marked improvement in their predictive capability was noted. In particular, extended indices based on L₁₀ (18 hour) and L_eq appeared to be useful predictors of community response to all of the traffic flow situations studied in this project.     

Evaluation and analysis of traffic noise from the main urban roads in Beijing

Traffic noise surveying and analysis was performed along three main roads in the Beijing urban area—the 2nd and 3rd ring roads circling the central downtown area and Chang-An Avenue, a major east—west corridor road through the heart of the city. The results indicate that these main roads are overloaded by traffic flow during daytime and noise levels due to road traffic along these roads are above relevant environmental standards by 5 dBA. The spatial variance of traffic noise was also analyzed, with the results indicating that the spatial differences result primarily from the unbalanced development of Beijing's urban districts.