Human response to railway vibration in residential environments : exposure-response relationships and modifying factors

ror understanding me wide variation in annoyance reactions, i^esuiisinvestigations made on factors coming into play when consideringThis thesis aims to contribute to the knowledge of human response to vibration inresidential environments and identify factors of primary importance whenconsidering exposure-response relationships from railway vibration. It has previouslybeen shown that annoyance increases with vibration magnitude. However, thesecorrelations between annoyance and physical ratings are weak. This suggests thatvibration-induced annoyance is governed by more than just vibration level, and thatsimple exposure-response relationships alone do not provide sufficient informationfor the reactions. Results ofanexposure-response relationship between level of vibration and annoyance arepresented here.The factors investigated were time of day, situational factors, demographic andattitudinal factors. This was achieved using data from case studies comprised offace-to-face interviews and internal vibration measurements (N=755) collectedwithin the study "Human Response to Vibration in Residential Environments" by theUniversity of Salford. Exposure-response relationships were estimated from ordinallogit models.It was found that exposure-response relationships between annoyance scores andvibration exposure were strongly influenced by two attitudinal factors (propertydamage concern and expectations about future levels of vibration). One situationalfactor (location of the property) and one demographic factor (Age) were found tohave an important effect on annoyance whereas visibility of the railway and time spent at home showed small but statistically significant influence. Time of day whenthe vibration occurs was also shown to play a role in the self-reported annoyance,with evening and night-time being the most sensitive periods. The additionalannoyance is equivalent to 17 dB for the night and 8 dB for the evening for a rms Wks\ of 0.01 m/s in the day. The relation between activity disturbance and exposuresuggests that sleeping and resting are the activities most affected by railway inducedvibration. These results indicate that future railway vibration policies and regulationsfocusing on community impact need to explore specific scenarios and new vibrationindices in order to facilitate an optimal assessment of railway effects on residentialenvironments