Dr. Ronan Glynn:

NPHET is in favour of avoiding all non-essential travel in the first instance. This is the most important measure. Beyond this, our advice is there and it is published. We have asked for mandatory quarantine previously and recently we asked for any element of discretion as it applies to travel to be removed insofar as is possible. However, we are not the experts on what is possible.

What we want is a situation where essential travel is reduced to the greatest extent possible, through whatever means are required to bring that into effect.