The EU-wide deployment of on-board and trackside ERTMS will improve interoperability, increase capacity and reinforce rail safety, therefore enabling the conditions for a Single European Railway Area. However, a series of difficulties including the increasing divergences of applying the ERTMS technology nationally and the absence of a business case for railway undertakings are putting ERTMS on the verge of losing its original purpose. Avoiding a derailment of ERTMS urgently requires a new joint approach. (....)