Generally, the speed limits in Singapore on the one lane roads, school zones, HDB, private and slip roads are 40 km/h, the normal ordinary one lane road is 50 km/h unless stated. All roads and expressways do have speed limits up to 90 km/h.
Offenders who caught speeding between 6:30am and 12:00am will be fined and given demerit points as follows:
Offenders who caught speeding between 12:00am and 6:30am will be fined and given demerit points as follows:
References
Speed limits in Singapore Wikipedia(Text) CC BY-SA