This European Standard specifies criteria to categorize road traffic noise reducing devices according to basic mechanical performance under standard conditions of exposure, irrespective of the materials used. A range of conditions and optional requirements is provided in order to take into account the wide diversity of practice in Europe. Individual aspects of performance are covered separately in the annexes. Safety considerations in the event of damage to noise reducing devices are covered in EN 1794-2. This European Standard covers the current behaviour of the product. In order to assess its long term performances, EN 14389-2 should be used. NOTE – The test procedure described in Annex A doesn't consider the fatigue effect.