Railways (both for freight and passenger) play an essential role in the global target of CO2 reduction. Therefore, existing railway lines’ capacity must be increased by means of higher speed, axle loads, and frequency while ensuring safety, reliability, and availability. A balance between investment (CAPEX) and operation/maintenance (OPEX) needs to be achieved in which railway-induced vibrations, therewith geotechnics, play an important role. Examples of overcoming challenges in predicting railway vibration and the effect of railway vibration on the track itself (and therewith on the maintenance) and also on adjacent structures will be presented. The showcases include case studies and applications of semi-empirical and analytical approaches as well as advanced numerical modeling tools in railway projects worldwide. The application of the above methods leads to an optimized design of the railways and, thus, an increase in sustainability. International practices concerning assessing railway vibrations will be discussed. Actual vibration measurement data will be compared with the modeling predictions to demonstrate the reliability of the different methods.