IMO Sengkang expansion should cater to:
156 > Clementi (Stops outside Compass1)
159 > Toa Payoh (Stops outside Compass1)
965 > Woodlands (dedicated pax to Yishun/Woodlands can board
here. Those for Compassalve St can choose 83/371/LRT).
* New feeder service to Anchorvale Crescent should operate from
main interchange. So also 372 even if it calls outside
Compass1.
* If there is new service to Tampines, it can start from
expansion.
But looking at CBP that has only 2 services after introduction,
I am expecting Sengkang expansion to have only 3 services to start
with. Maybe in future, more may get added.
IMO, the existing services that should use the new facility
should be 156, 159 and 372, because they also call at the bus stops
next to Sengkang MRT Station (#67401 and #67409), so re-locating
them would have minimal inconvenience for the commuters. This is
because the new facility is quite far from Sengkang MRT Station.
The only bus services that should use the new facility are the ones
that call at the bus stops mentioned above. Therefore, I think 965
should remain at the current facility.
Similarly, any new bus services at the new facility should also
call at that pair of bus stops.
Anyway, the current facility has sixteen parking bays, while the
new facility would have twelve. Currently, Sengkang Bus Interchange
has eleven bus services (not including 83). If 156, 159 and 372 are
re-located to the new facility, the current facility would have
eight services left - which is just nice, since the current
facility can only accommodate up to eight bus services.
If three bus services go over to the new facility, this means we
can have three new bus services at the new facility, as the new
facility can only accommodate up to six bus services. Well, the
assumption is that only three existing services are going over to
the new facility, while the rest remain at the current
facility.
Whatever the arrangement, Sengkang Bus Interchange can only have
three more bus services, because the current and new facilities
altogether only have twenty-eight parking bays. Three should be
enough, since Sengkang is already quite matured. IMO, the only
areas in Sengkang that need new bus services are Anchorvale
Crescent and Compassvale Crescent. I guess two new feeders (273
& 274) and one trunk (to enhance intra-town connections in
Sengkang) should be enough.