As I said it's not my thing design objects, I even have not any 3D Tool (like 3D-Craft, PaintShopt and such), and have no interest (so far) in the learning curve of this kind of work. But the technology is already present in the game, RSC (and other creators) just haven't gone beyond to explore the thing.
If you have RSC B7 with default lights, you'll notice a kind of (still incipient and timid) circular 2D halo giving the feeling of brighther light. This halo should be even brighter and wider, and AFAIK they can be set for different LoD's, I just don't know how farther this works (Jerry said 20ms only, but I guess is much more, at least in the B7 you can see the soft halo even from far). That's what the old MSTS technology uses, and looks like is the same of the snow weathered effect (in Winter season) that has been added in some engines, ie a texture object (with alpha in the case of lights) overriding another object (the beam when turned off).
You can also notice this in SD75 (pics below), barely satisfactory when seen from an angled profile view, but not from a frontal view. Combining two objects (for profile and frontal views) with alpha and you'll get the 3D effect, like in the most of trees of game (two or more plain 2D objects giving the illusion of a 3D object, when combined).
RailWorksProc2 2012-07-21 16-22-54-45.jpg
RailWorksProc2 2012-07-21 16-23-06-92.jpg
RailWorksProc2 2012-07-21 16-23-13-89.jpg