On the RMWeb forum, which has a lot of knowledgeable people including many who work in the rail industry, the resulting discussion on signalling systems for single-track lines and how they might be improved includes positive words for the software testing profession.

The system itself would be cheap, but the testing needed to demonstrate that it’s safe (and idiot proof) to the appropriate regulatory authorities is going to be quite expensive. Proper software testers(*) aren’t cheap.

From what I can tell, the Italian system appears to be a variation on the Telegraph and Train Order system without the use of either a physical single-line token or a virtual equivalent, a practice long since superceded in Britain. There is a far higher risk of human error leading to a fatal accident.

Though there have been quite a few head-on collisions in Britain resulting from conflicting movements across junctions, including the Ladbrooke Grove disaster, I can only think of two single-line collisions in the past century, at Abermule in 1921 and Cowden in 1994. That’s some safety record.