Elsewhere on this blog you can read about the world’s shortest international flights, 8 minutes between small cities in Germany and Switzerland here .
For scheduled rail services, the record would be held by the frequent metre gauge shuttles between Johor Bahru (JB) in Malaysia and Woodlands in Singapore. This is about 3 km.
Trains no longer run to the main terminus in Singapore. From JB there are connections to all parts of Malaysia and the Thai border.
At 1.08 you can see a metre gauge brake van of the same type used in IR.
The timetable can be seen here.
Until recently, Indian railfans could see ex-IR YDM-4s on the express trains between Singapore and Kuala Lumpur.
Now we come to another short international rail journey of about 50 metres on standard gauge – more of a joke, really:
As mentioned in the text, only children are carried as passengers on this short run between the Czech Republic and Germany. As they are Schengen countries, there are no border checks.
You may notice that the background music shifts from the Czech national anthem to the German one as the border is crossed.