The safety of railway line sections against strong winds can be improved by setting up anemometers in locations where wind speeds frequently exceed the critical wind speed of overturning. In order to ensure optimum location of the anemometers, wind speed values need to be estimated over an N-year return period along railway lines. This paper introduces a method to estimate over a given return period the values of the maximum instantaneous wind-velocity along railway lines at interval of 100m, by using two kinds of numerical simulation techniques (the meteorological model and the Computational Fluid Dynamics model) and a topographical factor analysis.