Has something to do with trains. Always precedes SET_MISSION_TRAIN_AS_NO_LONGER_NEEDED.
May be true that it can be used with trains not sure, but not specifically for trains. Go find Xbox360 decompiled scripts and search for 'func_1333' in freemode.c it isn't used just for trains. Thanks for the info tho.
Btw, func_1333 ends up calling this func which uses this native,
void func_1338(int iParam0)//Position
ENTITY::SET_ENTITY_COLLISION(iParam0, false, 0);