Interestingly, the Swiss railway system publishes real-world figures on its Co2 efficiency per passenger-kilometer. [https://www.mobitool.ch/de/tools/vergleichsrechner-15.html, german-only, un nfortunately]

They report some 80 passenger-km per liter of Diesel equivalent energy, compared to 13 passenger-km in a modern hybrid. Both values include the energy production, utilization and energy expenditure for infrastructure.

This assumes a modern network with electric trains though. I'm not sure if the article you cited still uses diesel-powered trains to arrive at such extremely different figures.