Level crossing (LC) safety is a crucial issue for railway operators and infrastructure managers. Accidents at LCs give rise to serious material and human damage, while seriously impacting the reputation of railway safety. In particular, some typical scenarios are behind the main part of train-car collisions which occur at LCs. On the other hand, ERTMS (European Rail Traffic Management System) is the standard railway control-command and signaling system being currently implemented throughout Europe and elsewhere. The aim is to ensure railway interoperability while enhancing safety and competitiveness of railway transportation. ERTMS specifications only provide a rough description when dealing with level crossing control. The present study elaborates on a functional control architecture for automatic LCs in the context of ERTMS operation Levels 2 and 3. Indeed, these operation levels ensure a continuous knowledge of train location thanks to the GSM-R (Global System for Mobile communications - Railways) link between the trains and the Radio Block Center (RBC). Hence, the established LC control scheme aims to ensure an optimal LC command based on the information regarding the train location and, thereby, prevent some potential risky scenarios and improve the global safety at LCs. To achieve this, a generic methodology is employed. Firstly, a formal behavioral model is developed using the Time Petri Net (TPN) notation. Then, the problem is formalized on the basis of the established TPN, in such a way as to carry out a sound and trustworthy analysis. The various steps of the developed approach are detailed and illustrated in the course of the paper. To the best of our knowledge, this is the first work that seeks to elaborate a control strategy of automatic LC in the ERTMS operation context.