[eru]

> In Singapore there is no MRT congestion prices only for private cars, right?

Singapore charges for MRT rides, but it's not explicitly a congestion charge. Every once in a while they experiment with discounts for off-peak train usage, which can sort-of be interpreted as a congestion charge.

> Trains get crowded but still workable.

At the peak of rush hour you sometimes have to wait three or four trains before one comes that still has standing room. (It's not as bad as it sounds, because during rush hour trains come every three minutes or so.)

IMHO, varying train charges more with congestion would make a lot of sense; but the system as it is works well enough that it's probably not worth for any technocrat to spend the political capital to seriously do anything about it.