In article ,
Michael Bell wrote:
Pi being what it is, on field where there is no preferred direction, an
orbital route will be shorter than an in and change and go out the other
side route for a journey of upt to 120° rotation round the city centre.

Except that using an orbital route is normally 3 trips (one in or
out to the orbital route - Poplar to Canning Town, say; one round
- Stratford to Highbury, say; and one in or out again - Highbury
to Walthamstow, say).

The two changes as opposed to one change makes it unattractive to
many; hence the relative usage of the NLL (4 - 6 3 carraige trains
an hour) against the Central (30 or so 6 car tph).

Still, they're great if you don't need to make one of the three
trips because you're a walk from the orbital route - like me.

--
You dont have to be illiterate to use the Internet, but it help's.