This report discusses and describes how a correction for the road surface can be introduced in models used for prediction of traffic noise along roads. There are two important purposes in introducing a road surface correction, partly that better prediction accuracy is achieved, partly that it encourages the choice of "low noise road surfaces". A survey is first made of how different calculation models outside the Nordic countries handle the question of road surface correction. Thereafter an account - in tabular form - is given of the road surface corrections that are desirable in order to obtain the best accuracy, and also simplified versions are presented where the overview is better. The different better. The different trade-offs are then discussed. The report suggests that the road surface correction will not be introduced at present in the Nordic traffic noise model (NTM) as compulsory. However, two tables are introduced as an Appendix in NTM. The tables contains correction terms for road surface based on measurement results obtained over a long period of time. (A)
Samenvatting