from wat i noe, the situation of 191:
morning and evening peak is NAC, S shift, though it extends till
quite late i think.
afternoon, a 284 AC bus which did morning E shift, rested, then
crosses over to do the afternoon part while the NAC bus goes back
to depot. when the NAC bus comes out at 4 plus, the AC bus goes
back to do 284 until about 7 plus and go back to bbdep. the 191 NAC
goes back to arbp/bbdep around the same time as well.
saturdays and sundays is 1 AC bus (FAC), T shift.
