Comparison of Road Traffic Noise Prediction Models: CoRTN, TNM, NMPB, ASJ RTN

Abstract

This research investigates the prediction accuracy of Calculation of Road Traffic Noise (CoRTN), Traffic Noise Model version 2.5 (TNM), Acoustical Society of Japan-Road Traffic Noise (ASJ RTN) and Noise Propagation Computation Method Including Meteorological Effects (NMPB). A test case model was constructed to investigate the combination of ground effect and shielding in each methodology. The predictions for CoRTN are implausible, because predicted noise levels for soft ground are equal to hard ground in some locations. This anomaly was not present in predicted noise levels from TNM, ASJ RTN and NMPB for the same test case. Noise levels for a rural freeway and an urban freeway were predicted for each methodology and compared with noise monitoring results. CoRTN resulted in high over-prediction. TNM and NMPB produced similar results, with TNM predicting slightly higher on average and NMPB having the lowest standard deviation in the prediction error. ASJ RTN resulted in high under-prediction.