Traffic related noise is currently considered as an environmental pollution. Paper presents results of multidirectional study attempting to serve urban traffic without the need to erect noise barriers interfering urban space. Initial concept of the road expansion included construction of 1000 m of noise barriers dividing city space. Improvement in the acoustic conditions after construction completion is possible due to the applied noise protection measures: vehicle speed limit, smooth of traffic flow, use of road pavement of reduced noise emission and the technical improvement of the tramway.
The author investigated traffic flow quality on a new 2+1 long road bypass with an exceptionally high share of heavy vehicles in order to assess rational limits of heavy vehicle shares in traffic flow, dependent on the length of the 2+1 road and the number of passing segments in each direction. This paper presents the results of traffic flow quality analyses through the use of empirical and simulation methods for a single 2+1 road segment with additional passing lanes, as well as for the study of the entire section of the bypass – 2+1 road. Variables include analysis of travel speed distribution, platoon traffic, and amount of passing maneuvers. Results show that large passing demands lead to very high speeds (over 100 km/h) on segments with additional passing lanes. The conclusions include remarks related to the use and operation of 2+1 cross-sections with high shares of heavy vehicles.
One of the basic parameters which describes road traffic is Annual Average Daily Traffic (AADT). Its accurate determination is possible only on the basis of data from the continuous measurement of traffic. However, such data for most road sections is unavailable, so AADT must be determined on the basis of short periods of random measurements. This article presents different methods of estimating AADT on the basis of daily traffic (VOL), and includes the traditional Factor Approach, developed Regression Models and Artificial Neural Network models. As explanatory variables, quantitative variables (VOL and the share of heavy vehicles) as well as qualitative variables (day of the week, month, level of AADT, the cross-section, road class, nature of the area, spatial linking, region of Poland and the nature of traffic patterns) were used. Based on comparisons of the presented methods, the Factor Approach was identified as the most useful.
In this paper, impact of changes in parameters of offered traffic on the accuracy of determining the parameters of overflow traffic in hierarchical systems with multi-service traffic was presented. Pascal type traffic streams were offered to the considered systems. The study investigated the impact of changes in the number of sources, intensity of traffic offered by individual classes, as well as changes in the traffic offered by a single free source. The presented results are based on determined relative errors of the values of overflow traffic obtained in simulations and on the basis of calculations.
The article introduces a novel Internet diagnosis utility - an open source IP packet snifferwhich captures TCP and UDP packets sent and received by a single Linux process only. Preliminary evaluation results are presented. The utility can be applied in the field of IP traffic classification.
The paper shows a study on the relationship between noise measures and sound quality (SQ) features that
are related to annoyance caused by the traffic noise. First, a methodology to perform analyses related to
the traffic noise annoyance is described including references to parameters of the assessment of road noise
sources. Next, the measurement setup, location and results are presented along with the derived sound quality
features. Then, statistical analyses are performed to compare the measurement results and sound quality
features. The included conclusions are focused on showing that the obtained loudness values, regardless of
the used system, are similar in a statistical sense. Contrarily, sharpness, roughness and fluctuation strength
values differ for the tools employed.
In recent years adverse processes of suburbanization have been observed in cities. It has become a serious challenge for urban and transport planners, as it influences largely the quality of space, the quality of life, and the cost of running the city. This paper is dedicated to travel models in areas serviced by a railway system, and is based on a real-life survey example of the Błonie community, a district belonging to the Warsaw metropolitan area. Research carried out in 2014 focused on combined travels behaviors recorded using GPS locators as well as quantitative research (volumes of users across various transport systems).
The aim of the article was to determine the course of changes the urban space under the influence of tourism, on the example of selected areas in Cracow. A literature study, statistical data and field studies were used to explain the relationship between the growth of tourist movement and the development of the tourist space of this city. The impact of tourism on changes in public and private space use within Matejki Square and Pawia Street, in the neighbourhood of the historical zone (Old Town) and in the New Square at Kazimierz, was analysed. The conducted analysis showed three functional changes of the studied areas under the influence of the rapid tourist movement. They were transformed from residential-service to service-residential related to service of tourists (hotels, gastronomy, trade, entertainment). The urban space has been enriched with elements that increasing the tourist attractiveness of Cracow compared with other cities, for example, concerning spending free time (pubs, cafés, restaurants), and the new accommodation base near the city-centre. A lack of a zoning plan and development vision causes the helplessness of the local authorities in managing the tourist infrastructure development, which is reflected at the Kazimierz New Square.
This article discusses the traffic types typically used in industrial networks. The authors propose a number of methods of generating traffic that can be used in modeling traffic sources in the networks under consideration. The proposed traffic model have been developed on the basis of the ON/OFF model. The proposed solutions can be applied to model typical traffic types that are used in industrial systems, such as Time-Triggered (TT) traffic, Audio-Video Bridging (AVB) traffic or Best Effort traffic. The article discusses four traffic models with modifications and shows how the proposed models can be used in modeling different traffic types used in industrial networks.
The existing traffic noise prediction models in road intersections relate mainly to the typical solutions of intersection geometry and traffic organisation. There are no models for large and more complex intersections such as signalised roundabouts. This paper presents the results of studies on the development of a traffic noise prediction model for this type of intersection. The model was developed using a multiple regression method based on the results of field measurements of traffic parameters and noise levels in the vicinity of signalised roundabouts in Poland. The obtained model consists of two groups of variables affecting noise levels at the intersection. The first group determines in detail the influence of traffic and geometry of the closest entry. The second group shows the influence of more distant noise sources (traffic at the three remaining entries of the intersection) and the influence of the dimensions of the entire intersection. The developed model was verified through additional field measurements, as well as compared to the results of two methods of traffic noise prediction: the French ‘NMPB-Routes-2008’ and the German ‘RLS-90’. The obtained results confirmed a higher accuracy of calculations performed using the developed model in the range of: −1.2 dB ÷ +1.0 dB, while the ‘NMPB-Routes-2008’ and ‘RLS-90’ calculate precision were respectively: −2.8 dB ÷ +1.3 dB, and +0.8 dB ÷ +5.2 dB. Therefore, the developed model allows for a more accurate prediction of noise levels in the vicinity of signalised roundabouts in a flat terrain without buildings and noise barriers.
In the paper, the simulation PROP5 program is used to predict the sound level in proximity of a road with defined surroundings. The simulation involves road geometry (number of lanes and their positions) and traffic structure (vehicle flow rates and their average speeds), with equivalent omnidirectional point sources representing vehicles. In Part I of the paper, the agreement between measurement and simulation results is tested to verify the accuracy degree of the applied models of a road, as a noise source and propagation throughout surrounding space. In Part II, using the pre-tested simulation program, the possibility of acoustic climate improvement has been analyzed.
n the paper, the simulation PROP5 program with the road model defined as a noise source and road surroundings model, is used to predict the efficiency of noise protecting means for the chosen building. The appropriate models of verified accuracy have been chosen by comparison of the simulation results with field measurements (Walerian et al., 2010). Here, using the pre-tested simulation program, the possibility of acoustic climate improvement has been analyzed in the ranges of practical variations of the input parameters. The road parameters: its geometry (number of lanes and their positions) and traffic structure over lanes (vehicle flow rates and their average speeds) have been taken under consideration as changeable parameters, that could be corrected to obtain acoustical climate improvement. Moreover, an acoustical screen designing has been considered. The screen efficiency has been evaluated under conditions defined by the input parameters of the road and its surroundings.
Enhanced Traffic Management System (ETMS) stores all the information gathered by the Federal Aviation Administration (FAA) from aircraft flying in the US airspace. The data stored from each flight includes the 4D trajectory (latitude, longitude, altitude and timestamp), radar data and flight plan information. Unfortunately, there is a data quality problem in the vertical channel and the altitude component of the trajectories contains some isolated samples in which a wrong value was stored. Overall, the data is generally accurate and it was found that only 0.3% of the altitude values were incorrect, however the impact of these erroneous data in some analyses could be important, motivating the development of a filtering procedure. The approach developed for filtering ETMS altitude data includes some specific algorithms for problems found in this particular dataset, and a novel filter to correct isolated bad samples (named Despeckle filter). As a result, all altitude errors were eliminated in 99.7% of the flights affected by noise, while preserving the original values of the samples without bad data. The algorithm presented in this paper attains better results than standard filters such as the median filter, and it could be applied to any signal affected by noise in the form of spikes