Transportation noise investigation and modeling in selected roads in Metro Manila, Philippines

Transportation is one of the most pronounced sources of noise pollution in urban areas. Frequent and excessive exposure to noise may negatively impact human behavior and performance which may also result in hearing damage especially for noise levels above 70dB. Philippine standards provide little emphasis on noise generated from traffic, with no local transportation noise models that can be applied in noise regulation or project evaluation. Equivalent sound pressure levels (Leq) along nine selected roads in Metro Manila were collected to determine whether the resulting noise levels are within the existing allowable standards. Multiple linear regression (MLR) and artificial neural network (ANN) models were then estimated to relate transportation noise to its contributing factors such as vehicular volume and vehicle mix, among others. Results show an average Leq of 70.806dB, which is not significantly greater than the 70dB threshold, nor the 75dB stipulated by local standards. The developed MLR and ANN models exhibited reasonable accuracy with R2 values of 0.88 and 0.85, respectively. Given the strong correlation of transportation noise with total traffic volume and percentage of heavy vehicles, a recommended mitigation measure is to restrict access of heavy vehicles along select thoroughfares or impose time periods allowing road access.