The main noise indicators used for noise level measuring and mapping of road traffic are L_day (L_d), L_evening (L_e), L_night (L_n) and L_{day-evening-night} (L_den). These are long-term averaged noise levels, determined over correspondent periods of the day. Day (07:00 16:00), Evening (16:00 - 23:00) and Night (23:00 - 07:00 next day) as per the “Gulf Cooperation Council” (GCC) Standards [1]. All of these indicators are defined in terms of A-weighted decibels dB(A). The L_den (Level day-evening-night) is a measure to the noise pollution of the environment. The use of the Lden was required in all European countries as of 2004. This was connected with the implementation of the European Environmental Noise Directive. The equivalent sound level per period over a whole year expressed in dB (A). At the evening and the night value is then a penalty factor of respectively 5.0 and 10.0 dB (A). This is because a certain noise level in the evening and the night from the environment is perceived as more annoying than the sound during the day. Another reason is that more stringent requirements are given for any sleep disturbance during the night. The Lden is the logarithmic mean of the day, evening and night value, using an “energetic averaging”. This means that the length of each period (Day = 9.0 hrs, Evening = 7.0 hrs, and Night = 8.0 Hrs) is also taken into account. The acoustical indicators described in the table below are long-term averaged noise levels defined in terms of A-weighted decibels dB(A). .