can't ride the monrail

[TinkerTina]

first noticed it in kings row. so i ran back to atlas. and when told to use the train to rescue manticore. i still couldn't ride the train. anyone else notice they can't ride the train?

[Prototelis]

There are two trains, the one in the alcove on the far right only lets people off.

 

The main one in the middle is the one you want. If you run up to it and you can't click the doors, wait a few seconds. That train will leave and you should be able to click the doors on the next one when it comes to a complete stop.