The implementation of recent guidelines for tunnel construction in Germany leads to extended air pressure variations inside trains and reduces pressure comfort for railway passengers. A questionnaire survey with 262 passengers revealed that pressure variations are rated less important for riding comfort than climatic and spatial aspects (study 1). A laboratory experiment (study 2) in the pressure chamber at the DLR Institute of Aerospace Medicine with 31 subjects (mean age = 37.7, SD = 12.7; 51.6% male) investigated the effects of systematic pressure variations on discomfort. The pressure changes (pressure increases and decreases) ranged from 1 to 100 mbar and were realized within 1-100 s. We derived thresholds for healthy passengers by means of random effects linear and logistic regression analysis. Logistic dose-response curves revealed amplitude/time combinations leading to a certain percentage of passengers perceiving discomfort (e.g. 50% dissatisfied passengers regarding a pressure increase of approximately 30 mbar within 5 s). The findings may help design engineers to meet passengers' comfort requirements.
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