Trying to create a moving train that slows and stops at stations

[Novian]

Thanks very much for the help, I've made some good progress.  Having a new issue that perhaps you can help me with?  I need to create a train that has 10 cars.  I have 2 so far but when I try to add a third I am having trouble getting the new car to be positioned correctly.  When I first create it (duplicating from the car in front of it) I can set the Position no problem.  After 1 time running the game the position is off (too large of a gap).  So I go to adjust it and now the value is constantly clamping back to the "gap" value.  I am unable to change it.  Any advice?  Thanks!

See attached image for ref.  If I set it to any value other than the 941.269 shown it instantly snaps back to that value.