Hey!! Somebody could say why the ERA is interesting in the study for the Interoperability of the 1,520 mm (4 ft 11⅞ in) system gauge? When the focus was the standar 1,435 mm (4 ft 8½ in). I cant understand it!
http://www.era.europa.eu/core/interoperability/Documents/Recommendations/IU-1520-20080831-Final-Report_v3-01.pdf