Bus Eireann is advising that, under the level 5 restrictions from tomorrow night, Bus Eireann and Expressway services will only operate at a 25% capacity.
Under Government advice, all travel should be limited within a 5km radius, unless travel is essential for work, education and other essential purposes.
Only one seat out of every four can be used on buses, and these are being reserved for essential workers.
Bus Eireann says passengers should not use buses if they're experiencing any symptoms of the virus, and public transport should not be used to travel to or from a Covid-19 testing centre.
Irish Rail is also reminding the public that all rail travel is for essential workers and essential purposes only.