fa Railway track and structures Railway track and structures پژوهشي Research In this study, a new approach for the evaluation of horizontal curve design in railway tracks integrating safety criteria is proposed. To conduct this research, a vehicle-track interaction model is developed in ADAMS Rail program and simulation of dynamic vehicle response from derailment point of view is followed. Using this model, sensitivity analyses are made on the main geometry parameters of horizontal curves, including radius, super-elevation and transition length, considering different speeds. Consequently, the influences of each parameter are investigated on governing derailment criteria i.e. overturning, Nadal and Prud’homme. The obtained results form the basis for further practical charts by which, both the geometry design and safety evaluation of railway horizontal curves can be determined. A practical use of the new approach is finally presented to indicate its capability and applicability. Rail track, Geometry design , Horizontal curve, Safety, Vehicle-track interaction 63 72 http://ijrare.iust.ac.ir/browse.php?a_code=A-10-176-4&slc_lang=fa&sid=1 Masoud Fathali m_fathali@mail.iust.ac.ir 180031947532846001944 180031947532846001944 No School of Railway Engineering, Iran University of Science & Technology, Tehran, Iran Fereidoon Moghadas Nejad 180031947532846001945 180031947532846001945 Yes Department of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran Hamid Moghadam Ali 180031947532846001946 180031947532846001946 No Islamic Azad University, Science and Research Branch, Tehran, Iran