French jurist said:Average cost of eliminating such a crossing in France is around 3/4.5 million EUR (non urban areas I guess).
Here, in an urban area, if it costs like 20 million pesos each and if there are 300 of those in the city (no idea, just an approximation ?) = 6 billion pesos.
There are many projects that are currently working to eliminate grade crossings, although most focus on grade crossings of the Mitre, San Martin, Urquiza, Roca and Belgrano rail lines. The Sarmiento line, where this accident took place, is currently not being considered for any quick grade crossing solutions due to a megaproject nfk & cfk announced about 6 years ago to run the sarmiento completely underground that had never gotten started. (they finally got around to put up the signs earlier this new, but nonetheless have not started anything).
Of course completely underground rail in Urban Areas is the final solutions with the old rail way being used as biking/walking paths, but this needs to be done slowly. It would be best in my mind for the government, either city or nation, to put the sarmiento in a slightly below grade open tunnel so they can create street bridges above the line. OF course there are many engineering problems, and people just don't have the political will to commit to this fixing this problem, which will inevitably cause problems in the service during the time the solutions is being worked on...