Abstract

The IMAGINE railway traffic noise source model is described, which is a further elaboration and completion of the Harmonoise model. Within the EU project Harmonoise, a model was proposed including most of the main railway noise sources. In the IMAGINE project, complete formulation was put forward taking all relevant physical sources but also main operating conditions into account, and default source data was proposed. At a given section of track with a given traffic flow, for each type of rolling stock, a combination of operating conditions and physical sources may occur. The operating conditions are constant speed, acceleration, braking, curving and stationary operation. The physical sources are rolling noise, impact noise, traction noise, curve squeal in points or curves, broadband or tonal braking noise and aerodynamic noise. The IMAGINE models for each physical source are presented and their relevance for each operating condition is discussed. Some examples of default input data are given and measurement methods to obtain source data are outlined.

Abstract

One of the most difficult and expensive tasks in making noise pollution maps is the collection and processing of the data needed to create acoustic models. In the case of road traffic noise maps, obtaining speed data for light and heavy vehicles a problem that has usually been avoided by using a road's speed limit or by making assumptions based on experience from similar road types. Here global positioning systems-based techniques are applied for acquiring vehicle speed data and adapted to fulfill the requirements of noise prediction models. © 2009 Elsevier Ltd. All rights reserved.