Presently its 7 plus 4, 11 buses at maximum/peak plus two OS.
After implementation, plus one more split that would likely do 189A
trips only for morning peak (original plan was to have opposite
direction evening peak), and OS from 947/970, possibly converting
them to run 189A or add in OS from other services to run the SWT
(latter not likely), the aim would likely be diverting working
folks to take 189A and spread out the load to prevent cramming at
Bukit Batok Ave 1 onwards. At my bus stop below my residence, there
will always be cramming from 0745, sometimes on to late
0900hrs.
No doubt this is an improvement, but the problem can hardly be
solved if it only involves one additional split and would worsen,
of course, when regular shifts are called in to do 189A. Rainy days
would affect the frequency adversely, sometimes up to 20
minutes.
After all these years with s189 (amounting to 11 this month),
this is one of the sound, yet might not be practical, plan to deal
with increasing commuters heading to the new WCEGA Plaza and Tower
and Midview Building/Bukit Batok Cresent factories/offices.