the 500 enforcer aint new post, those are existing station staff(which all along are alrady supposed to enforce those rule) or redeployed folks from other areas.
anyway, mrt is a business private business entity thats gov linked, but not entirely under them. Why LTA involved coz anything thats on the road of singaland and involved transport, they are the one to go to. And if you wanna find out more, can try searching for infos dating back to the early 80s where gov decided to build mrt and how a faction of the MRT group became the LTA of today..
oh, and the finiancial report of smrt is an open thingy, since they are public listed. But inside just numbers and numbers words so small that unless knowing whats about, if not, its hard to understand whats going on.