The tanks reported near the border north of Kiev are not just on trains, either. Take this video (which we are still working to verify) reportedly showing Russian tanks on the ground and on the move near Novozybkov, which is just north of the Ukrainian capital. If these tanks are where the video says they are, they’re within an hour from the Ukrainian border.
Tanks are usually transported by rail or trailer to their destination. Tanks on the move signify that they are ready for combat.