Confirmed 1.8.7/Mac. Definitely looks like the push vector is stuck as described by @unknown. Observations with a 12x12 loop of track:
furnace cart started at southwest corner while facing northeast comes to rest at northwest corner (about 10 blocks from northeast corner where its motion vector presumably gets set to 0)
furnace cart started at southwest corner while facing southeast comes to rest at northeast corner (about 10 blocks from southeast corner where its motion vector presumably gets set to 0)
Nick Iaconis
Confirmed 1.8.7/Mac. Definitely looks like the push vector is stuck as described by @unknown.
Observations with a 12x12 loop of track:
furnace cart started at southwest corner while facing northeast comes to rest at northwest corner (about 10 blocks from northeast corner where its motion vector presumably gets set to 0)
furnace cart started at southwest corner while facing southeast comes to rest at northeast corner (about 10 blocks from southeast corner where its motion vector presumably gets set to 0)