ROAD TRAFFIC NOISE ANALYSIS AND ANNOYANCE IN MOROCCAN CITIES: CASE OF RABAT

摘要

In this work, measurements of the daily noise levels of road traffic were conducted in Rabat. A total of thirty points were selected and for which the road traffic is the principal source of noise. For each point, extensive measurements of L_(eq)(A weighted) and statistical A weighted levels (L_1, L_5, L_(10), L_(50), L_(90), L_(99)) were made using a Solo 01dB sound level meter class1. All measurements were carried out with 20 ms sampling period from 8h am to 19h pm. A detailed analysis of spatial variance of the measured RMS acoustical pressure using non parametric statistical tests have been developed as well as regression equations between L_(eq) and statistical levels. It was shown that correlations are less good for L_(90) and L_(99) than that for L_1, L_5 or L_(10). In addition, the annoyance was evaluated by estimating the L_(den) from L_(50) and using published relationships between the L_(den) and the percentage of annoyed population. It is pointed out, as in our precedent work that the minimum measurement period that gives an estimate of the hourly L_(eq) with an errorless than 1% is about of 15 to 20 minutes. This result is important for optimal future measurements planning.