OK, as a long time visitor to Ireland (more than 20 years of summer and Christmas vacations) and now a permanent resident since 2020, let me tell you that the Irish, while a lovely people, are incredibly impatient drivers. And that's a gender neutral assessment. My husband in a Yoda-like moment of profundity once calmly said as we struggled to get on the M1 roundabout on-ramp just north of the city, that "the Irish are alway speeding because they're constantly stopping for a chat and are always late." And that seems like a fairly accurate assessment of both the joviality of the Irish character and their reckless abandon on the highways and byways.
The thing is, if you're a good, confident and cautious driver, you will be fine. One of the first things I learned, especially on the rural roads no wider than a U.S. standard home driveway, is that if a local is raging down the local roads doing twice the speed posted, simply pull aside and let them by; don't make it a match of wills, that will only make you, the driver, more anxious, and anger the locals.
I recently got my Irish driver's license and what amazed me about taking the written test is that Irish rules of the road emphasize politeness, especially out in the country. The rules focus on how to avoid tractors, large trucks and wayward herds of cattle and sheep. And folks, by and large, obey the rules, if you're on a narrow road going down a hill, good, courteous drivers going up the hill know to pull aside and stop to let you by, and you acknowledge these kindness with a small wave, which you receive in return.
There are some rules that for a U.S. (read, California educated) driver seem odd: You can't make a left on a red light at an intersection even if there is no traffic or pedestrians. When stopped at a major intersection, you have to shift the car to Park, etc. There is one thing that I would keep an eye out for, though. The Irish are very family-oriented and they love their children, and everyone else's children, for that matter. So when driving in school or creche zones, you need to be incredibly attentive and cautious. I would argue its these zones, in the morning and afternoon, where Irish drivers are most attentive and law enforcement is most observant.
Overall, the Irish people abide by the driving rules (at a faster clip than is advised, mind you), but — and this isn't uncommon anywhere on the planet — most accidents are caused by males under 25, often one-vehicle accidents, though side-swiping and rear-ending are the most common. Young men are the same worldwide, apparently.