Human response to environmental noise and vibration from freight and passenger railway traffic
There is currently a push to increase the proportion of freight traffic that is transported by rail, which is argued to be a safer, more sustainable and more climate friendly means of freight transportation when compared with road or air transportation. This will result in increased noise and vibration from freight railway traffic, the potential impacts of which are not well known. The aim of this research, therefore, is to further the understanding of the human response to freight railway noise and vibration.\ud Data for this research comes from a field study comprising interviews with respondents and measurements of their vibration exposure. A logistic regression model was created and optimised, and is able to accurately classify 96% of these measured railway vibration signals as freight or passenger signals based on two signal properties that quantify the duration and low frequency content of each\ud signal. Exposure-response relationships are then determined using ordinal probit modelling with fixed thresholds and cumulative ordinal logit models. The results indicate that people are able to distinguish between freight and passenger railway vibration, and that the annoyance response due to freight railway vibration is significantly higher than that due to passenger railway vibration, even for equal levels of exposure. To further investigate this disparity in response, a laboratory study was performed in which subjects were exposed to combined noise and vibration from freight and\ud passenger railway traffic. Through the technique of multidimensional scaling, the subjective responses to these stimuli were analysed to investigate the specific attributes\ud of the stimuli that may lead to the difference in human response. The results of this study suggest that the perception of combined railway noise and vibration takes into account not only the exposure magnitude of the noise and vibration stimuli, but also signal properties such as duration, spectral distribution and envelope modulation. These parameters, and in particular the duration parameter,\ud appear to account for the difference in the human response to freight and passenger railway vibration.