>(As many have pointed out, that's why not using the X-tracks at
>Embarcadero is so stupid -- since it takes longer, it
>_decreases_ the number of trips per vehicle.)
In an emergency situation, the Embarcadero diamond is still used to
turn back trains. This occurs when there is a blockage in one or
both of the pocket tracks in the MMT. I hate to say this, but the
onset of ATCS is that we don't have to use the slow, cumbersome
Embarcadero crossover for regular service any more. This in itself
is a big improvement.
Peter, the problem with the crossover was the fact that it was unique
and that it was a single point through which all trains on the entire
system had to run. It was "slow" only because contention for paths
across this single point caused tunnel-long backups.
Two additional turnback locations in the MMT (and others at Folsom and
Fifth/King) should have _added_ to this turnback point, adding
additional flexibility. The original west-of-Embarcadero crossover is
in fact vastly faster to use (single it involves no magic mystery
tours of MMT) and no less "cumbersome" than the MMT turnbacks. For
this reason it should be used by preference (when changing ends at the
platform won't cause backups), rather than as a last resort.
The baby has been thrown out with the bathwater.
(And please, ATCS didn't buy use of MMT: it was Muni Capital Project's
inexcusable and incompetent decision to make MMT depend on ATCS, not
some inherent pre-existing signalling limitation.)