The map ? shows how far you can travel by train from Geneva in 5 hours (nice tool here: www.chronotrains.com). What does that tell us about travel by rail as alternative to air?
? High-speed rail is required to connect cities – in this example, Paris, Lyon, Marseille
? Connectivity between high-speed rail is required – in this example, it takes up to one hour to change train station in Paris which is why it takes more than 5 hours to reach any other city in France from Geneva
? Connectivity across borders is required – in this example, the distance to Paris and Munich from Geneva is the same, but the time by train is double when traveling to Germany.
It would be interesting to see a similar map for 5-hour journeys including flights…