Hi Kyholm
Currently the MPS system is accessible only to Trainz Plus and Gold Membership subscribers.
However, we haven't yet announced what may happen in the future, and we do have plans to expand the MPS system in future, and this may also include options to open it up to more people. We are still assessing the data requirements, and bandwidth requirements, for MPS routes. It is worth noting that this is still a first stage implementation, and there are still a few things that aren't yet implemented or completely finished that would otherwise be expected if it were a 'fully released' feature 
So as to ensure that all members are seeing the same thing, and it is only accessible to those who have access to the feature, it currently works through our servers and cannot be hosted through a LAN only. This also ensures the persistent nature of MPS, allowing anyone with access to the route to be able to access it at any time. We don't currently expect this aspect will change.
Regards
Zec Murphy
Customer Support Rep
N3V Games (Auran)
*Please do not use Private Messages for support. Support can only be provided via the helpdesk, or via the forums.