From 25th of June to 10th of July Latvian Railways will begin testing on-the-go border checks for Rīga - Moscow night train. This will reduce the journey time by two hours.
Other recent technological improvements have already cut the journey time by 40 minutes. So now the 920 km journey will take just 13 hrs and 40 minutes instead of the 16 hrs and 21 minutes just a few years ago.
That's still a quite miserable average speed of less than 70 km/h though. And indeed for some reason the up to 20 coaches long train accelerates very slowly. We have regional DMUs with more stops than the Moscow sleeper but they're faster.