My floor, I take it --
This question is to do with a country which was a participant in the First World War for the whole length of that conflict. Shortly before WWI, two different railway companies built and opened main lines across a part of that country, in rough and difficult terrain, aiming for broadly similar destinations. In a situation of what many might regard as "commercial competition gone berserk": over a distance of 160-odd km., the two lines were laid out and built absurdly closely parallel to each other -- pretty much, within sight of each other the whole way. In 1917, by government decree, this stretch of route(s) was made over into one single track, the use of which the two rivals were obliged to share -- the recovered rails etc., were sent off for use at or near the battlefront. (A few years later, both companies were merged within one overall undertaking.)
Please identify the country concerned; and, as accurately as possible ("marking" is planned not to be too ferocious) -- the area of the country / rail route(s) where this took place, and the two railway companies.
