Definition of light size for airport feature

[PeCa_Chuck]

I’ve been testing around the light object for runway/taxiway light, after getting some ideas for new 3d model.

Fortunately, I successfully made a “dot” of light in-game world, by using PrimT and pType 0.
However, just can’t figure out the way to get much bigger light source which can be seen in airport construction.
Such lights on the side of runway/taxiway doesn’t look like dots. They look much bigger even you are close to it.

Does anyone know how to get it?