Evaluation of the equivalent level in the case of traffic noise in Isfahan,Iran

Traffic noise is considered as one of the important sources of noise pollution in urban areas. day-time urban noise quality assessment was studied in chaharbagh bala street in isfahan that has the combination of critical zones,therapeutic,educational,commercial,residential and touristic. the aim of this study is to determine the equivalent noise level (laeq30) by metric castle 450 made in the england. since the chosen square is a clear hotspot for traffic noise in a large city,the measurements of equivalent level noise in this street performed at 8 stations leading to azadi square in order to obtain a 12-h noise level. intersections of hezarjerieb,shariati,pol hotel and nazar (in 2 lanes of north and south or east and west) at 8-12 of morning and 17-21 of evening with 3 replications on weekdays and! compared with standard 60 db. the volume of traffic was also quantified by reproducing video camera recordings. the highest mean leq of 83.67 dba was observed in hezarjerib educational- residential- commercial zone followed by,79.47 dba in shariati residential- hospital zone at morning,77.48 dba in nazar residential- commercial zone and the minimum was 62.18 dba in pol hotel residential- touristic- commercial-zone at evening. all observed leqs were above the statutory limits that is 60 db. in addition,measurements in the timeframe of 30 minutes showed that the rate of travel of the vehicle is very high. the noise measurement clearly indicated the alarming condition of noise pollution.