Effective lightning protection measures are essential for railway signalling systems because suspended operation or train delays due to lightning damage may cause social disruption. The authors therefore measured lightning overvoltages on level crossing systems (representing typical examples of wayside signalling equipment) in the event of substantial lightning, enabling quantitative analysis of the frequency of lightning overvoltage occurrence and the collection of basic data for the consideration of countermeasures against lightning. As a result, it was possible to estimate the occurrence probability of lightning damage caused by exceeding the withstand voltage of the level crossing system.