Critical analysis of day time traffic noise level at curbside open-air microenvironment of two types of road network of a big city

Aim: The aim of the research work is to critically analyze day time traffic noise level (Leq) at curbside open-air microenvironment of two types of road network of Kolkata City, India. Methods: 280 sets of data on road width, traffic volume, Leq, peak (L10) and background (L90) noise level were collected from curbsides of 23 major roads. The data was sub set according to the following road network types i.e., one-way traffic in single or double lane (RN-1) and both-way traffic in single lane (RN-2). Noise Climate (NC) and Traffic Noise Index (TNI) were computed for both types of road network. Results: After sub setting of data the number of sets of data accounted for 234 and 46 for RN-1 and RN-2 type of road network. The ratio (RN-1/RN-2) of the averages road width and traffic volume of two types of road network was 2.28 and 1.89. The ratio of the average Leq, NC and TNI of two type of road network was 0.98, 0.89 and 0.94. The ratio of the average L10 and L90 of two types of road network was 0.99, 1.01. Conclusion: RN-1 type of road network was wider and also had higher traffic volume in comparison with RN-2 type of road network. On the contrary RN-1 type of road network was quieter and less annoying in comparison with RN-2 type of road network. Lower Leq of RN-1 type of road network in spite of higher traffic volume was attributed to lower L10.