The new breed of digital trains – not to be confused with the airport shuttles that we have been riding for years, or the Docklands Light railway in London which travels on a confined track – will share the tracks with conventional driver-operated trains, in a much more complex environment.

Trains are already an efficient method of moving people and goods around but can be 15 per cent more energy efficient when driven by an AI, be more punctual, and can carry 30-50 per cent more passengers or freight, by reducing spacing between trains, all on existing infrastructure. Rural public transport economics can also be transformed by making lines less expensive to operate and enhancing existing safety levels.

The last few months have seen a flurry of announcements that, at first sight, might appear to herald the imminent arrival of autonomy on the rails. This is not the case, but progress is being made. In November 2021, a Japanese bullet train operated by East...