I know no one actually plays Ultimate Ride games anymore, but I am doing this for myself, and while I say these are intended for Ultimate Ride, they can be available for NoLimits unless they have a polygon limits. As far as I'm concerned, Ultimate Ride games doesn't have issues with models over 90k tris, but I heard RCT games have huge issues with those. I'll leave you guys to guess what it is I'm modeling and what I am going to make for UR games and perhaps NoLimits if anyone wants.
On the side note, I am learning Industrial Design, so I don't really have much time these day.