# Assessment of Road Noise Pollution in Urban Residential Areas--A Case Study in Pitesti, Romania
## 2 Materials and Methods  
Recently, in accordance with the computer systems evolution, a new generation of measuring equipment has emerged, incorporating computers and operating software dedicated to measuring and analyzing road traffic noise-the new concept of integrated road traffic noise assessment system [30; 31; 32]. For example, it has become possible to eliminate occasional noise peaks (such as those caused by the passing of an intervention vehicle), which would alter the measurements [33; 34; 32]. When using just raw data, without further processing noise level measurement results, there will be higher peaks values, affecting the outcome. An integrated monitoring and evaluation system may respond to notification tasks regarding exceeding the permitted noise level, noise mapping requirements, continuous noise monitoring or for calculating parameters and impact assessment. Such a system can perform reporting and informing the public while all information and data are stored. Regarding the noise level measurement equipment used for conducting experimental research, the Noise and Vibration Laboratory of the University of Pitesti has modern equipment to make noise measurements, among which the ones used to make traffic noise measurements are presented. Figure 1: The roundabout intersection and the overpass road from the Podul Vilor. The LD 831 Digital Portable Sonometer (Figure 2) is a high-precision digital sound-level meter, microprocessor-controlled, accuracy class 1 according to IEC 651 and IEC 804. The LD 831 sound level meter has the following technical characteristics [32; 33; 34; 35; 36; 37]:  
* Weighting filters: A (responds to sound same way as the human ear), B, C, 1/1 or 1/3 octave (16 Hz-20 kHz);
* Dynamic range in excess of 120 dB;
* Peak level measurement: <50 ms;
* Measuring range: 0.125 s-12 h.  
The meter is designed to measure sound levels in the civil and industrial sectors for statistical analysis, to verify compliance with noise pollution laws in urban and industrial areas, and to measure in difficult acoustic environments. The display shows the sound level in decibels, usually with a descriptor showing the selected time and frequency weight combination (e.g., \(\mathrm{L_{Aeq}}\) or \(\mathrm{L_{Apeak}}\)). SAMURAI (SINUS Acoustic Multichannel Universal Realtime Analysis Instrument) is a software package for sound and vibration measurement and real-time analysis [33]. The calibration of the measuring equipment was carried out before the measurement site was measured, requiring a correction to be made by the atmospheric pressure of \(-0.1\) dB. The measurements are carried out according to specific requirements for the road noise measurements (microphone height 1.30 m from the road and 1.00 m from the roadside) in the immediate vicinity of the currents of vehicles from the intersections. A first research will consist of making noise measurements in a time interval at a traffic light intersection, to highlight its variation as a result of the traffic composition variation of in the measuring section (vehicles of different categories) and of the travel regimes (the vehicle stopped, with the engine running at idle, at the red signal of the traffic light, respectively, the vehicle in accelerated motion at the appearance of the green signal of the traffic light). The second experimental research will consist in determining the noise physical and psycho-physical indicators at the main intersections of the city central area and their comparative analysis-for traffic light intersections and for roundabouts. To identify how road traffic determines noise pollution, it is required for noise measurements to highlight both the physical indices of the road noise (which are determined only by the physical characteristics of the road noise) and the psycho-physical indices (which characterizes the degree to which man is affected by noise) [41; 42].