43 has bi-directional heavy loading in certain points. I'll tell
you PM since I have more experience.
Direction from UEC to Punggol
- Marine Parade to Paya Lebar
- Paya Lebar to Serangoon
- Serangoon to YCK Road
- Buangkok MRT to Sengkang East Rd
Direction from Punggol to UEC
- Buangkok MRT to Buangkok Green
- YCK Road to NEX (depends on 70, 103 arrival time)
- Paya Lebar MRT to Marine Parade.
Even before 7am, 43 frequency is also higher towards Punggol.
Not many people take 43 from Buangkok Green to Buangkok MRT anyway,
most people take 43/43M from Buangkok Green to Serangoon MRT.
Also, overlapping loading patterns often resulted in pax being
left behind at the first bus stop of YCK Rd in SBST times, when
there were too many SDs, only to have huge number of pax alight at
the second stop. But at least for YCK Rd, there is also 70.
I'm not too sure about the Marine Parade sector, as I rarely
have time to go there.