Traffic Noise Simulation Research Articles

Validation measurement of vehicle pass-by models for dynamic urban environments

Simulation and auralization of urban traffic noise can help city planners and residents to improve existing urban areas or plan new attractive living spaces while enabling discussions about shared auditory experiences, regardless of expertise. Evaluating street noise in the context of urban areas requires careful consideration of their urban surroundings, such as landscapes, buildings, and other structures. Obtaining measurements to validate simulations may be difficult given the variety and complexity of sounds within an urban setting. Recreating the real urban scenario on a test track, e.g., including building facades and exact source and receiver positions, helps validate simulations but also poses challenges due to varying road surfaces, weather conditions, and disturbances such as industrial or fly-over sounds. This research represents a method of bringing a measurement set-up consisting of source (e.g., vehicle), receiver (e.g., pedestrian), and surfaces (e.g., walls) to the more controlled environment of a hemi-anechoic chamber. The method is intended for the validation of previous vehicle pass-by measurements by utilizing sine sweeps with walls parked at varying distances. These environments aim to deliver more insight into the relevance of diffracted sound for configuration of urban sound simulation models.

A Prediction Method for City Traffic Noise Based on Traffic Simulation under a Mixed Distribution Probability

Predicting and assessing urban traffic noise is crucial for environmental management. This paper establishes a traffic noise simulation method based on microscopic traffic simulation, utilizing a traffic simulation under a mixed distribution probability combining normal and exponential distributions. This method integrates a single-vehicle noise prediction model to compute the spatial distribution of noise. Comparison with empirical data demonstrates that the proposed model effectively predicts the level of traffic noise. The accuracy of the model is validated through comparison with measured data, showing minimum and maximum errors of 3.60 dB(A) and 4.37 dB(A), respectively. Additionally, the noise spatial results under microscopic traffic models are compared with those under line source models, revealing that the proposed model provides a more detailed and realistic noise spatial distribution. Furthermore, the noise variation patterns between stable and time-varying traffic flows are investigated. Results indicate that noise levels fluctuate under stable traffic flow, whereas under time-varying traffic flow, noise values exhibit a stepped change.

Dynamic traffic noise simulation at signal-controlled intersections based on cellular automata model

Predicting and assessing road traffic noise is a crucial task in urban environmental management. To accurately predict traffic noise at signal-controlled intersections, this study introduces a dynamic traffic noise simulation model based on cellular automata. Firstly, a cellular automata traffic flow model for a multi-lane signal-controlled intersection is established. The vehicle noise emission and noise propagation models are incorporated into the dynamic simulation of traffic flow to accurately calculate traffic noise. Subsequently, the simulated data is compared with the measured data. The results demonstrate that the proposed method can effectively predict the statistical distribution of traffic noise at the intersection, with prediction errors of less than 2 dB(A) for Leq, L50, L90, and less than 3 dB(A) for L10. Finally, the proposed method is employed to simulate the operational status and noise emissions of vehicles at intersections under various traffic conditions. Based on the simulation results, the intrinsic connection between traffic operation and noise emission is explored, and the characteristics of traffic noise emission and distribution at intersections are analyzed. The method and its findings are anticipated to serve as a valuable reference for the management of road traffic noise.

Impact evaluation of different network planning concepts on traffic noise

The purpose of this paper is to study the impact of road structure on traffic noise from an urban network planning perspective, to provide solutions to control and prevent traffic noise at source. The process is divided into three parts. Firstly, the stochastic user equilibrium model for traffic flow allocation is improved to be more accurate. Secondly, a global traffic noise simulation method is proposed for the network based on the noise prediction model, and the noise data is visualized. Finally, a noise evaluation system is established to study the traffic noise evolution patterns under different road structures. The results show that with the increase of network density, the traffic noise value of the network decreases. The layout of one-way roads will reduce the regional traffic noise value. The impact of road grade adjustments on traffic noise is positively correlated with the rate of change in road capacity. The study can provide an effective basis for control traffic noise from the network planning stage.

A process‐driven geo‐analysis engine to support online collaborative geographic experiments

AbstractGeographic experiments, as a comprehensive research approach, are utilized to explore natural and social worlds. To help geographically dispersed people engage in geographic experiments and improve experimental outcomes, online collaborative geographic experiments have received increasing attention. As a new generation of geo‐analysis tools, VGEs (virtual geographic environments) can provide computer‐aided tools to serve geographic experiments. They can not only provide the collaborative GIS capabilities, but also implement geographic simulations using different cyberspace dispersed geographic models. For the complicated and interaction‐intensive online collaborative geographic experiments, VGEs also need to help experts implement geographic experiments following a well‐defined process. Nevertheless, the process is hardly considered in the existing support systems of collaborative geographic experiments. Therefore, we clarify the categories and relationships of interactions during the process of collaborative geographic experiments and design a process‐driven geo‐analysis engine. Through this engine, participants can maintain the processes of their collaborative geographic experiments, as well as implement interactions throughout the entire process. To verify the capability of the engine, it is used to support the case study on traffic noise simulation. The results suggest that the engine could assist the different geo‐analysis applications with a well‐defined process.

Simulation and Analysis of Road Traffic Noise among Urban Buildings Using Spatial Subdivision-Based Beam Tracing Method

In order to realize the simulation and evaluation of road traffic noise among urban buildings, a spatial subdivision-based beam-tracing method is proposed in this study. First, the road traffic source is divided into sets of point sources and described with the help of vehicle emission model. Next, for each pair of source and receiver, spatial subdivision-based beam-tracing method is used in noise paths generation. At last, noise distribution can be got by noise calculation of all receivers considering the complex transmission among urban buildings. A measurement experiment with a point source is carried out to validate the accuracy of the method; the 0.8 m height and 2.5-m height average errors are about 0.9 dB and 1.2 dB, respectively. Moreover, traffic noise analysis under different building layouts and heights are presented by case applications and conclusions can be reached: (1) Different patterns result in different noise distributions and patterns designed as self-protective can lead to an obvious noise abatement for rear buildings. Noise differences between the front and rear buildings are about 7–12 dB with different patterns. (2) Noise value might not show a linear variation along with the height as shielding of different layers is various in reality.

Simulation of traffic noise both indoors and outdoors based on an integrated geometric acoustics method

An integrated geometric acoustics method is presented for calculating both indoor and outdoor traffic noise distributions. This approach is divided into three phases: spatial subdivision, path generation, and noise calculation. First, spatial subdivision is applied outdoors. Then, sound paths are generated outdoors via beam tracing and indoors via ray tracing through structure trees. For indoor receivers, sub-beams that enter the building are defined, and their paths are generated by searching the hunting zone. Finally, using the determined paths, both indoor and outdoor noise values can be calculated. A case is used to evaluate the accuracy at various frequencies; the method yields more accurate results with mid-high-frequency sounds compared with low-frequency sounds both indoors and outdoors; at the dominant frequency of 630 Hz of traffic noise, the indoor and outdoor average errors are 1.45 dB and 0.55 dB, respectively. Moreover, the effects of the building position and the interior structure on traffic noise are discussed. The following conclusions are obtained: 1) The noise levels in the front portions of buildings are much higher than those in the rear portions, in both the entire space and individual rooms, and as the floor number increases, the attenuation increases as the distance and complexity of the path increase. 2) The influence of the interior structures on the noise distribution is strong. With the same area for each type of room, the noise effects in the bedrooms and the drawing room in strip-type houses are the strongest; after comprehensive consideration, the foursquare-type house is recommended.

Research on rapid detection and control mechanism of urban traffic noise impact based on Soundplan software simulation

With the rapid development of Chinese modern urban residential area, the car ownership has increased dramatically. This leads to a phenomenon that traffic noise is increasingly endangering people’s living environment quality. Noise not only can cause tinnitus, hearing loss but also can cause cardiovascular disease. Since the 1970s, a lot of countries have established the road traffic noise simulation models based on the local actual situation, which already have been revised and perfected in the application. Based on the simulation of Soundplan software, we try to analysis the influence of road traffic noise of Zin Jin apartment in Tsinghua University and propose a set of suitable design strategy.

Areawide dynamic traffic noise simulation in urban built-up area using beam tracing approach

Modeling areawide traffic noise in both space and time domain is a tedious work, especially in urban built-up area. A smart, accurate and rapid method was developed specifically for fixed grid sources and receivers(S-R), which consisted of the precomputed S-R attenuations in off-line, dynamic traffic noise simulation in real time and a database to connect two parts together. In off-line part, beam tracing approach was used to simulate sound propagation among buildings, taking multiple reflections and diffractions into consideration. Firstly, the spatial subdivision was used to subdivide 2D space into a series of order triangles, and then beam tracing algorithm recursively traced beams through these triangles, which was represented by beam tree data structure. In real-time part, the dynamic simulation of traffic provides time-variant input of traffic flow parameters to vehicle emission model, which was then assigned to the nearest source. After deducing S-R attenuations from database, dynamic immissions at grid receivers are obtained by summing up sources inside their circular viewport. Therefore, the outputs (Ln, Leq and LNP) were available to assess the noise pollution levels on a spatial and temporal scale. A part of Zhujiang New Town in Guangzhou was chosen as a validation area, measurement results were in general good agreement with simulations.

Dynamic simulation and characteristics analysis of traffic noise at roundabout and signalized intersections

Traffic noise prediction is an important topic for traffic environment planning in cities. The complex traffic flow at road intersections makes the prediction of traffic noise challenging. In this paper, a dynamic traffic noise simulation method based on microscopic traffic simulation is used to study the traffic noise near roundabout and signalized intersections. A vehicle noise emission model that considers the effect of acceleration is established using an experimental method. The accuracy of the model is verified by comparison with measured data. Traffic noise near roundabout and signalized intersections under different traffic volume levels is simulated, and the results are compared. Some significant relations between traffic noise and traffic volume are obtained, and the mechanisms are analyzed. The results show that traffic noise reaches an upper limit when traffic is saturated, and the noise energy contribution of the exit lane is far greater than that of the entrance lane.

Dynamic Simulation of Traffic Noise by Applying Ray Tracing Method based on Indoor Space Partitioning

This study presents a revised 3D ray tracing method by combining it with indoor space partitioning. This method divides an entire indoor space into limited convex polyhedron subspaces, and thus reduces the number of surfaces intersected with rays, and omits the validity test of the collision point on the reflecting surfaces. Combining it with a microscopic traffic simulation tool and a vehicle noise emission model, and taking the influence of diffraction into account, the method can be utilized in simulating dynamically the process of traffic noise diffusing inside the building through windows. Meanwhile, this study selects two different types of indoor architectural layouts in order to demonstrate the efficiency of this method, the influence of diffraction and of the state of windows, and the differences in indoor noise on different floors. A comparison study on before-and-after indoor space partitioning shows that the method is efficient.

Rendering of Dynamic Road Traffic Noise Map based on Paramics

Traffic flow is simplified as equal-interval line source in traditional road traffic noise prediction models. The prediction results of these models are non-dynamic and can only be used to render the static noise maps. This paper performs the dynamic simulation of road traffic noise by integrating traffic micro-simulation technology, noise emission and propagation calculation, and accomplishes the dynamic rendering of traffic noise distribution based on Paramics platform. By designing and developing Paramics plug-ins, the dynamic traffic noise map is generated by real-time rendering of the spatial and temporal noise distribution data through the traffic simulation. High validation is indicated from the study case of Zhujiang New Town in Guangzhou.

Traffic noise monitoring and simulation research in Xiamen City based on the Environmental Internet of Things

The Internet of Things (IoT) has many potential applications in the field of environmental monitoring. In this article, some hardware, including noise meters, ZigBee, and GPRS, were assembled and adjusted to get traffic noise data, which would be analyzed and compiled into a database based on the categories and characteristics of the data. Based on traffic noise data from 35 roads of nine green spaces in Xiamen, we used a back propagation neural network to practice net-simulation of noise data from 30 roads, while data from the remaining 5 roads were used as test data. Finally, the trained neural network was used to simulate traffic noise from 100 roads in Xiamen Island. Software systems using VB language and Flex network technology were also developed, and the simulation results were published on the Internet. The success of the method indicates that the Environmental IoT not only enables fast and effective acquisition of environmental data, but also enables accurate simulation and real-time network distribution.

3D Analysis and Investigation of Traffic Noise Impact from Hemmat Highway Located in Tehran on Buildings and Surrounding Areas

This study analyzes and investigates the impact of traffic noise on high rise buildings and surrounding areas by the side of Hemmat Highway that links west of Tehran to the east. In this study, a 3D traffic noise simulation model is applied on a GIS system. Visualized noise levels are formulated by the proposed model for noise mapping on all surfaces of the buildings and surrounding ground in a 3D platform. The investigation shows that there is a high traffic noise impact on the foreground and front facades of buildings, rendering these areas unsuitable for residential purposes. The ground area by the sides of buildings and the building side panels receive a lower noise impact. Most of these areas are still not acceptable for residential and even commercial use, only the back yards and back panels, have the lowest traffic noise impact. It also shows that the building height is not an effective factor for reducing motorway noise on the upper part of the building. Finally, construction cantilever barriers with a height of seven meters, close to the outer edge of the highway was presented as an effective way to reduce noise within the allowable range of noise pollution for commercial and residential purposes.

Dynamic simulation and characteristics analysis of traffic noise at signal-controlled pedestrian crossing junction

Experiments were carried out to measure the noise emission levels in cruise conditions and acceleration/deceleration noise adjustments were made for three types of single vehicles at a reference distance. Integrating vehicle noise emission model and propagation model, the traffic noise at a signal-controlled pedestrian crossing junction was simulated dynamically with real-time traffic flow data provided by microcosmic traffic simulation software. Finally, both the accuracy of simulation results and the practicability of this approach were verified by comparing the simulation results with the measured data. Some prominent characteristics of traffic noise near a signal-controlled pedestrian crossing junction were analyzed as well

Dynamic traffic noise simulation at a signalized intersection among buildings

Dynamic traffic noise simulation at a signalized intersection among buildings

3D analysis and investigation of traffic noise impact from a new motorway on building and surrounding area

This study analyzes and investigates the impact of traffic noise on the high-rise building and surrounding area by the side of a new motorway that links Bangkok to the new Suwannaphum International Airport and Pattaya. A traffic noise simulation model in 3D form is applied on a GIS system. Visualized noise levels are formulated in vectored contours for noise mapping on all surfaces of the building and surrounding ground in a 3D platform. Noise impact is then investigated based on this 3D noise mapping in LAeq,1 h noise contours. The investigation shows that there is a high traffic noise impact on the foreground and front façade of the building, rendering this area unsuitable for residential purposes. The ground area by the sides of the building and the building side panels receive a lower noise impact. Most of these areas are still not acceptable for residential use; however, all of the side panels and most of the ground area by the sides of the building can be used for commercial and business purposes. The back yard and back panel, together with the rooftop, have the lowest traffic noise impact. They are the safest places for use as residential areas, except for a small strip along the front edge of the rooftop. From this study, residential areas that are sensitive to noise impact must be located far away from the front façade and side panels of a building. It is also shows that the building height is not an effective means of reducing motorway noise on the upper part of the building.

Approach to road traffic noise issues : Development of road traffic noise simulation models

Approach to road traffic noise issues : Development of road traffic noise simulation models

Simulation of highway traffic noise with utilization of equivalent sound level of pass‐by vehicle

This paper presents study and building of a highway traffic noise simulation model by utilizing equivalent sound level over 20 s of passing‐by vehicular noise in the analysis of nine types of vehicular basic noise. The basic noise of each vehicle type is applied into the formulation of the main highway traffic noise simulation model. The coefficient of propagation and ground effect for this model is also estimated and applied to the highway traffic noise model. This highway traffic noise model is then tested for its goodness‐of‐fit to field observations. The testing result shows that this model provides an effective prediction for highway noise in Thailand.

Development of a highway noise prediction model using an Leq20 s measure of basic vehicular noise

The objective of the study reported here was to build a highway traffic noise simulation model for free-flow traffic conditions in Thailand employing a technique utilizing individual vehicular noise modelling based on the equivalent sound level over 20 s ( L eq20 s). This L eq20 s technique provides a more accurate measurement of noise energy from each type of vehicle under real running conditions. The coefficient of propagation and ground effect for this model was then estimated using a trial-and-error method, and applied to the highway traffic noise simulation model. This newly developed highway traffic noise model was tested for its goodness-of-fit to field observations. The test shows that this new model provides good predictions for highway noise conditions in Thailand. The concepts and techniques that are modeled and tested in this study can also be applied for prediction of traffic noise for local conditions in other countries.