Yup. It happens, especially in dual-operator area such as Woodlands
or Boon Lay.
Well, one bad thing about this thing is that sometimes, it can
get a little bit noisy, like BC go and horn for their friend's
attention on the road. Happen before.
One good thing is that it makes being a bus driver not that
boring. At least there are colleagues to make your day more
brighter.
Actually what I worry is that the horn might distract them if
they are driving. And you got the point right, that this makes
being in the driving (public service) sector not so boring.