We’re in agreement that night trains are a good thing, but you should push for them whether or not your trains are driverless.

You misunderstand my use of economic. Everything has a cost and a benefit which can theoretically be calculated, with infrastructure like transit that benefit extends beyond fares. Typically governments will do this calculation when deciding whether to pursue a new project, they include all the planning, construction, running costs, and externalities e.g. climate impact, and all the benefits from fares, economic activity, new opportunities for industries and development, ect. This produces a cost benefit ratio. In my research with transport, the best value projects are local safety improvements like cycleways, sometimes the ratio is as good as 10. Large public transport projects are maybe 1-2, and large motorways are usually less than 1. My point was a train driver is a small cost that isn’t going to significant affect this. Of course, this analysis often gets ignored and the overpriced motorway gets built anyway.