The National Transport Authority is reporting some services as 'full' this morning when taking social distancing into account.
It is anticipating more passengers as phase one comes into effect.
NTA chief executive Anne Graham says they have additional fleets running to cope with the added demand:
"We believe we have enough service out there, even with the social distancing in place, to be able to cater for this phase one of reopening.
"I've just had some feedback this morning that some of the services have definitely been busy and in some locations are actually full in terms of social distancing numbers."