Noise prediction for highways in Thailand

A model of highway traffic noise is formulated based on vehicle types. The data were collected from local highways in Thailand with free-flow traffic conditions. First, data on vehicle noise was collected from individual vehicles using sound level meters placed at a reference distance. Simultaneously, measurements were made of vehicles’ spot speeds. Secondly, are data for building the highway traffic noise model. This consists of traffic noise levels, traffic volumes by vehicle classification, average spot speeds by vehicle type, and the geometric dimension of highway sections. The free-flow traffic noise model is generated from this database. A reference energy mean emission level (the basic noise) level for each type of vehicles is developed based on direct measurement of Leq (10 s) from the real running condition of each type of vehicles. Modification of terms and parameters are used to make the model fit highway traffic characteristics and different types of vehicle.     

Geoinformatic prediction of motorway noise on buildings in 3D GIS

This study predicts and displays the impacts of motorway traffic noise on a nearby building, utilizing a motorway traffic noise model in combination with geoinformatic technique. Two- and three-dimensional geographical information systems are used to visualize noise impacts in the form of three-dimensional noise contour on the building and ground surface. The results offer a clear, visual display of impact levels from roadway noise in the form of noise contour overlay on vicinity area and building blocks along the roadway in three-dimensional form. The area can be turned and investigated at different angles.