ROAD TRAFFIC NOISE IN DOWNTOWN AREA OF TEHRAN

Noise pollution is a major problem for the quality of life in urban areas. the present study was conductedto determine the noise levels of road traffic at central area of tehran. it focused on one of the busy andcrowded square along with its 7 connecting streets, which had a heavy traffic and located in thedowntown of the city. total of lis measuring points were selected along the roads, pavements and in theshopping areas to adequately represent the different acoustically commercial situations. the measuringpoints were divided in to 4 site-groups namely; street. pavement shop and barrier each with 60. 40, 10,and 5 measuring points respectively. the measurements were carried out during a full week days startedon saturday morning and end on friday evening, the acweightcd continuous equivalent sound levelvalues, laeq; la max; la min; and the statistical levels: l1, l10, l50. l60 and l99 as well as the octave bandcenter frequencies sound pressure levels were manually measured at each point separately. the meanvalues of laeq for street. pavement. shop and barrier site groups were 78.5, 73.3, 68.7 and 70.8 dbarespectively and the overall mean of laeq was 74.7 dba. the statistical test (p