30 minutes in advance for a train? Sometimes I arrive a minutes in advance and just enter the train before it is continuing its journey. Happens when my connecting train had a delay.
In Switzerland, where the train schedule is stunningly efficient, you can do this very reliably. Check in and security procedures make this impossible with airports. Unfortunately, this is also an issue with international high speed trains (TGV) where there are queues and checks.
In Germany the issue is, there is enough money to plan and build motorways but not for train routes. Consequence is, that many routes are over capacity and cargo, local, and long distance trains share one track. The result is that one delayed train creates a wave of delays through the entire network.
Fortunately there are still a few hassle free international high speed trains in Europe. Travel between France and Germany isn't subject to any special security measures. You just get on the train. Sometimes the train stops at the border for a really quick check and that's it.
That works when it's a commuter train, but you can't plan on just showing up minutes before a high-speed train that assigns seats. Because you can't just hop on the next one.
That's most of the reason why you can't just show up at the gate of your airplane 5 minutes before they shut the doors.
Security is the only big difference. You gotta plan on it possibly taking 30 minutes.
