Noise is one of the most important sources of pollution in the metropolitan areas. The recognition of road traffic noise as one of the main sources of environmental pollution has led to develop models that enable us to predict noise level from fundamental variables. Traffic noise prediction models are required as aids in the design of roads and sometimes in the assessment of existing, or envisaged changes in, traffic noise conditions. The purpose of this study was to design a prediction road traffic noise model from traffic variables and conditions of transportation in Iran.
This paper is the result of a research conducted in the city of Hamadan with the ultimate objective of setting up a traffic noise model based on the traffic conditions of Iranian cities. Noise levels and other variables have been measured in 282 samples to develop a statistical regression model based on A-weighted equivalent noise level for Iranian road condition. The results revealed that the average L_Aeq in all stations was 69.04±4.25 dB (A), the average speed of vehicles was 44.57±11.46 km/h and average traffic load was 1231.9±910.2 V/h.
The developed model has seven explanatory entrance variables in order to achieve a high regression coefficient (R²=0.901). Comparing means of predicted and measuring equivalent sound pressure level (L_Aeq) showed small difference less than -0.42 dB (A) and -0.77 dB (A) for Tehran and Hamadan cities, respectively. The suggested road traffic noise model can be effectively used as a decision support tool for predicting equivalent sound pressure level index in the cities of Iran.