If that tragic and entirely preventable incident was the one I think, there was a similar collision in Germany more recently.
The cause? Inadequate signalling systems, relying on fallible humans to think the line ahead was clear yet being unable to ascertain this.
The "answer"? The cheap, cowardly way out: let the Police immediately treat the unfortunate station-master who unwittingly waved the train away onto an occupied line, as a criminal.
This was learnt way back in the 19C when rail travel was expanding rapidly in Britain, and once properly interlocked signals and points on block-operating systems, were introduced the incidence of collisions dropped to being very, very rare. No radios, no computers... instead, simple but very rugged and very reliable mechanical systems, with simple telegraphic and telephone communications between its human operators who were not acting alone but co-operating as a team.
Put simply both the Greek and the German drivers would have been unaware of a train approaching on the same line, but should have been held back by a big red STOP signal until the oncomer was safely past and the road clear. He might also have been able to see the points ahead, not set for his train. If not, that railway was poorly designed in the first place, and not put right since.
