They do the same with the fibre network in Singapore, too.
I think the British rail network might work on similar lines? The German electricity companies emphatically do not work on those segregated lines. There are some politically pushes every once in a while---Germany has some biggest price differentials between domestic and wholesale electricity prices (and some of the highest domestic prices), but the regulatory capture seems to be too much to overcome.
It can be implemented fairly easily by separating a company into two and forbidding them from giving special deals to their former counterpart.
That seems to have a very good effect on competition in practice...