fa Railway track and structures Railway track and structures پژوهشي Research Finding the optimal location of new stations along the rail transportation network is considered in this study by proposing a mathematical model. Two simultaneous effects on railway demand points (users) are investigated, namely, the time effect and the covered population which is achieved by constructing new stations. The better accessibility of demand points to rail network is considered as the positive one and the negative effect concerns the increased travel time induced by additional stops at newly constructed stations. Two objective functions are considered including the saved travel time and the covered population. The proposed model has been implemented as a case study on Tehran subway network and the results are presented. Railway Station location, Accessibility, Covering Population, Time of travel 123 131 http://ijrare.iust.ac.ir/browse.php?a_code=A-10-86-1&slc_lang=fa&sid=1 Hasti Jafari 180031947532846001791 180031947532846001791 No School of Railway Engineering, Iran University of Science & Technology, Tehran, Iran Masoud Yaghini yaghini@iust.ac.ir 180031947532846001792 180031947532846001792 Yes School of Railway Engineering, Iran University of Science & Technology, Tehran, Iran