What the travel restrictions are doing is trying to stop the spread of the virus. It is not to stop a person going from A to B to C, and if you are virus free the whole time there is no risk to anyone else from your travels. But the problem is you can have the virus and be unaware you are infecting others.
And it is all about risk management. So say in theory 100K people were planning to come from London to Ireland for Christmas. We were asked not to travel so 70K of those decided not to travel. Either they decided themselves because they have elderly relatives or the mammy got onto them and said please don’t come or whatever. That leaves the 30K who decide to come, and maybe 20K of those did the full 2 weeks of restricted movements before the Christmas dinner, all is good.
Then the last 10K. These are higher risk takers, they have been working away in London, travelling around, meeting less friends and family but still a few and all in all are happier and more comfortable with a bit higher risk than the other 90K. Maybe they are younger, or fitter, or the mam gave them a sob story about having to be home for Christmas. And they travel and sure they only met the mam & dad and ran into a few neighbours and brought gifts home from Mary who they met in London the day they travelled because she was too afraid to come and she wanted her gifts hand deliveries to the granny. And because they are slightly higher risk takers the statistics say that a few of them will have Covid, say 1%. And that 100 spread the B117 variant, and maybe there were just 1 or 2 who went on to be super spreaders. That is all it could have taken to make wave 3 go exponential.
Putting more travel restrictions in place is just trying to reduce the numbers of those higher risk takers. So we end up with only 10 of the 100 travelling and we have to think they are even higher risk because no one can persuade them not to travel and there is no way the Garda can arrest them and they do lots of things to bend and wriggle past the guidelines and regulations. But in my mind they are a serious danger to starting off another wave because they are much less cautious than the general population and take risks.
If we could find and segregate these few people it would be so much easier, but who can tell who they are because there is nothing to make them stand out. This is why the restrictions are crude tools trying to modify the behaviour of a small % of the population.
This is why I worry when I hear of people taking the risk of travelling because the act of travelling in a pandemic signals to me that they are risk takers and I might ultimately end up being infected because of their decisions.