Exceeding the permissible noise levels from rail transport in the Kysuce region

. Rail transport is a source of noise that has disturbing effects on the environment. Adverse noise emissions must be observed and at the same time keep the permissible noise levels that depend on the type of protected area given by the Slovak legislation. The paper deals with compliance and analysis of these permitted noise values in some selected locations of the railway line in the Kysuce region.


Introduction
Noise emissions represent a significant environmental burden on the environment. The largest polluters include transport.
Although the railway noise is considered to be less burdensome it is the second most dominant source of the environmental noise in Europe with nearly 7 million people exposed to levels above 55 dB L den in 2012 considering people exposed in urban areas. [1] The topography of the terrain, its absorption properties and obstacles on the way of spreading from the source, for spreading noise in the external environment is very important. The range and intensity of noise is also influenced by the substance through which it spreads. In the case of the spread of noise from railway transport in outside, it is air and its climatic conditions. However, the climatic factors are not considered in the paper and it will only deal with the spread of noise from rail traffic in the free space in the Kysuce region and its reduction, depending on the distance from the source.

permissible noise limits in transport
Unlike to road traffic, where permissible noise limits at the source have existed in the EU since the 1970s, noise standards for trains only came into force at the beginning of the twenty-first century [2] In 2007, Regulation 549/2007 of the Ministry of Health of the Slovak Republic, in which the permissible values of noise L Aeq,p for rail transport compared to the values defined in Government Regulation 339/2006 have not changed. This decree is still valid and in full wording the permissible limits are given in Tab. 1.
The noise levels are evaluated for the purposes of spatial planning and control at 1.5 m r 0.2 m above the ground outside the building or in a front of peripheral wall of a building, the noise are assessed at the distance of 1.5 m r 0.5 m of the wall and at 1.5 m r 0.2 m above the floor of the relevant floor levels. The Surroundings means the area within 100 m away from an adjacent axis of driving lane of road or from the axis of the adjacent railroad tracks [3].

Noise study in the Kysuce region
Measurements were carried out during the night-time on railway line No. 127 in various places in the village Čadca and Svrčinovec in 10 measuring points according to the valid Regulation.

Evaluation of the noise limits compliance
To evaluate the assessed values for comparison with the limit value under current legislation, the equivalent noise pressure level A -weighted sound pressure level is used. Equivalent A -weighted sound pressure level of the continuous sound L pAeq -timeaveraged mean A level, which is used to describe the sound with varying levels of sound. It is calculated as the sound pressure that is energetically equivalent to the long-term effects of intermittent noise or noise with varying sound level [4].
The sound pressure level was counted by the formula 1: -reference value of sound pressure, (2.10 -5 Pa), p A(t) -instantaneous acoustic pressure of the sound signal, (Pa).
The measured L R,Aeq,n value is measured value L pAeq, T increased by uncertainty of measurement U.
Uncertainty of measurement and sound prediction determined according the guidance No: NRÚ / 3116/2005 dated 2.5.2005. Classification of the measured noise, depending on the frequency composition and its directional properties, results in the resulting expanded measurement uncertainty U = 1.8 dB [5].
From the particular hour measurements of LAeq,1h noise events, which were not caused by railway operation were "cut out". The particular hourly noise levels were energy calculated by the formula [

Assessment of noise study in the Kysuce region
In-situ measurements of the non-modernised track were used to assess the value compared to the permissible value according to valid legislation, with the measurement points being chosen in the residential area beside of the railway track under consideration -in category of the area II.

Conclusions
In Tab. 3 all the measurement points are evaluated from the point of view of the territory category, it means the distance from the noise source and their compliance with the permissible values. The measurements were done before the modernization of the railway line. From the noise study it is clear that the following modernization of the railway line will require effective noise reduction measures. At all measuring points, the permissible noise values were exceeded for the night period. There is no visible effect of the distance from the noise source to the noise exposure level, because noise of the road and geographically rugged terrain also affected to the noise level.
Observance of nighttime noise level value for residential areas of category II. (45 dB) at the distance of 100 m to 200 m from the railroad is quite demanding. Compared with other countries (Fig. 2) it is clear that the Slovak republic belongs to the countries that have some of the highest permissible values in this area. There are partial results of the grant VEGA 1/0766/15" Research of noise emissions sources in the railway transport and methods of their effective reduction" in the paper.