Ireland is adopting a default 30 kmh (19 mph) speed limit in urban areas

That works very well in Wales already, and its saved dozens of lives. Also, as a driver you get to see a bit more off the town as you go through because you are travelling slowly. I'm happy with that.

Meanwhile where I live the state makes it illegal for the city to set a speed limit below 25 mph (40 km/h). 😭

Nice

Makes sense in context. Some of their two lane roads are narrower than a single lane in other places. Dealing with oncoming traffic is a game of chicken where someone will be going off road.

Works well here in Japan (though the police could enforce it better. Got passed by some jackass in a 30 no passing zone the other day in an area with poor visibility)

If only. The amount of times I've been cycling at 30km/h on a 30km/h street and still have cars pass me.

I was in a Canadian school zone today and thought that the posted speed, 40 km/h, should simply be referred to as "fast." It's 1.6× the speed of a four-munute mile and 10× walking speed. It's fast.

Stroads would be fast-and-a-half.

Intercity highways, ie. "back roads," would be double-fast.

Expressways, 2.5 fast. Triple-fast and beyond is certainly too fast.

The point is: anything that is fast is doable on a bike. Faster than that should be on rails or have a professional, full-time operator — not anyone who can pass an eye exam, and hold a No.2 pencil or click a mouse 40 times.

Fast is fast enough. If you need to go fast, go alone. If you need to go far, or faster than fast, go together.