I would suggest to skip Yishun Ring Rd entirely since it's
already covered by NR1. Might as well follow svc 859's route to
Sembawang:
Niteowl not necessarily start from Marina Centre.Revamp all
those Niteowl and Nightrider.
1N:Shenton Way-Yishun via Toa Payoh,Bishan,AMK & Yishun.
2N:RWS-Tampines via Mountbatten,Marine Parade,Bedok Reservoir
and Tampines.
3N:Marina Centre-Choa Chu Kang via Commonwealth,Clementi,Toh
Tuck,Bt Batok,CCK.
4N:Shenton Way-Pasir Ris via Geylang,Bedok North,Simei,Upp
Changi Rd,Pasir Ris.
5N:Marina Centre-Jurong West via Redhill,Commonwealth Ave,Jurong
East,Jurong West.
6N:RWS-Punggol via
Serangoon,Buangkok,Hougang,Sengkang,Punggol.
NR1:Shenton Way-Yishun via Serangoon,Potong Pasir,Upp
Thomson,Sembawang Rd,Yishun.
NR2:RWS-Tampine North via Victoria St,Geylang
Bahru,Bartley,Tampines central,Tampines North.
NR3:Shenton Way-CCK via BKE,Woodlands,BPJ,CCK
NR4:Marina Centre-Pasir Ris via Kallang,Geylang,Bedok
Reservoir,Tampines,Tampines Ace 10,PSR.
NR5:Shenton Way-Jurong West via Tanglin,Redhill,Commonwealth
Ave,Boon Lay,Jurong West.
NR6:Shenton Way-Sengkang via Potong
Pasir,Serangoon,Buangkok,Sengkang.