As at 7am this morning, some 11,000 travellers have crossed, according to the Immigration and Checkpoints Authority.
Fully vaccinated travellers can also cross in their own vehicles - and which hundreds did, bringing back the familiar sight of vehicles in long queues.
Prior to this, Malaysian workers who used to do the daily commute had to either be away from their families back home, or quit their jobs here.
Besides the daily commuters, the re-opening is seen to help kick start short trips from Singapore to Malaysia.
See also: Covid cases spike in Hong Kong, Singapore as new wave spreads
The re-opening was first announced by the prime ministers of both countries on March 24.
According to the government, Singapore and Malaysia are also progressively restoring other modes of transport, including cross-border public bus services.
See also: BioNTech beats estimates as vaccine maker pursues more diseases
The Woodlands Checkpoint run by ICA ... a familiar sight once again.
Travellers waiting to cross at 10.54pm, more than an hour before the opening.
The lines of travellers getting ready to make the crossing at 11.06 pm
