Atmospheric effects on traffic noise propagation have largely been ignored during measurements and modelling, even though it has generally been accepted that the effects may produce large changes in receiver noise levels. Measurement of traffic noise at multiple locations concurrently with measurement of meteorological data is described. Statistical methods were used to evaluate the data. Atmospheric effects on traffic noise levels were shown to be significant, even at very short distances; parallel components of the wind (which are usually ignored) were important at second row receivers; turbulent scattering increased noise levels near the ground more than refractive ray bending for short-distance propagation; and temperature lapse rates were not as important as wind shear very near the highway. A statistical model was developed to predict excess attenuations due to atmospheric effects.
Abstract