In this paper, a new unified method for estimating the representative noise evaluation index L_α(α=5, 10, 25…)of the road traffic noise in the case when various traffic controls are carried out to maintain the quiet environment(e. g. , near the hospital and school)in the large cities has been introduced on the basis of the observed evaluation value L_α before practicing traffic control. More concretely, the above method has been derived from two types of typically different viewpoints in the following:(i)A direct way of evaluating the effect of the traffic control on the noise evaluation has been given under the first introduction of the equivalent model on road traffic noise reflecting explicitly an effect of the change of traffic flow owing to the traffic control. Then, the change of noise level distribution has been quantitatively estimated by use of this model(See §2. 1). (ii)An indirect way of evaluating the effect of the traffic control on the noise evaluation has been given under the first introduction of a unified expression of the probability density and/or cumulative distribution functions of traffic noise, in the form of orthogonal and/or non-orthogonal expansion series reflecting concretely the change of the traffic noise based on traffic flow control in each coefficient(See §2. 2). Furthermore, by applying the results of this theory to the traffic noise data actually observed in Hiroshima City, the partial legitimacy of this method has also been experimentally confirmed.
抄録全体を表示