On the eight-mile stretch between Falahill and Stow, for example, the construction of narrow overbridges at Heriot and Fountainhall will scupper the prospects of doubling this section in the future.
Widening the spans of these two small road bridges from 5.5 metres to 8.7 metres would hardly seem to be bank-breaking.
First Minister Alex Salmond recently revealed his vision of special trains carrying visitors down the scenic line to Tweedbank and boosting the Borders’ tourist industry.
Sadly, this attractive proposition will only be possible by cancelling ordinary service trains, as there will be simply no room on the single line to accommodate these tourist trains.
Such is the rapid progress on the construction of the new railway, it is too late now to improve its capacity.
However, I suspect some of these new narrow concrete bridges will have relatively short lives before considerable sums have to be spent widening them.
Primrose Bank Road