Helsinki records zero traffic deaths for full year

> Argumentum ad populum [0] is itself an informal fallacy, as described on both of our links.

Which gets to the difference between one and the other.

"This is correct because everybody says it is" is a fallacy because it can be true or false independent of whether everybody says it is or not. Even if the premise is true, the conclusion can be false, or vice versa.

Whereas if the premises that X likely leads to Y and Y is bad are both true, then the conclusion that X likely leads to something bad is not independent.

> What I said wasn't an argumentum ad populum anyways: we're discussing definitions, and definitions do not have truth values.

Categories have definitions. Whether a particular thing fits into a particular category can be reasoned about, and a particular miscategorization being common doesn't make it correct.

> But not all incorrect premises are formulated in a reasonable manner. There are degenerate premises that have telltale signs of being misguided. These would be what make informal fallacies. In a way, you could think of them as being incorrect about the premises of what counts as sound logic.

The general form of informal fallacies is that they take some reasoning which is often true (e.g. if everybody believes something then it's more likely to be true than false) and then tries to use it under the assumption that it's always the case, which is obviously erroneous, e.g. the majority of people used to think the sun revolved around the earth.

The category error with slippery slope is that the probability is part of the argument. If 60% of the things people believe are true, that doesn't tell you if "sun revolves around the earth" is one of those things, so you can't use it to prove that one way or the other.

Whereas arguing that taking on a 60% chance of a bad thing happening is bad isn't a claim that the bad thing will definitely happen.

> especially in terms of door-to-door time

So in other words, your city made it extremely inconvenient to use anything BUT bikes to get around. Which is exactly my point.

Do an experiment, drop 10 points randomly within your city. Now plot routes between them using various transport modes. I bet that transit will be 3-4 times slower than bikes.

> I have basically zero reason to buy a car: even if there was zero traffic on the road it's not worth the quite substantial cost.

I guess you have zero kids, and your country has a collapsing population? The absolutely telling metric is the number of families with two or more kids, because it's the point where bikes become utterly inconvenient.

> But it is certainly possible to make road layouts that make safe cycling basically impossible, and American city planners seem to have mastered that

Oh yeah. I know that firsthand.

My neighborhood just got bikelaned. Now I have a traffic jam outside of my house half of the day, delaying thousands of people for at least 10 minutes every _day_. The local bus now takes 10 minutes more on average for the roundtrip. And all that for 30 meters of bike lanes. That is almost entirely unused because it ends up against the bottom of a steep hill.

But good news, everyone. Our new housing units are the smallest in the nation and our housing prices are growing fast despite the slowing economy!

Yes, that's why the second half of the equation is structural traffic calming: you both need to lower the speed limit and induce lower driving speeds. The US has historically not done a great job at the latter, and has mostly treated it as an enforcement problem (speeding cameras and tickets) rather than an environmental one (making the driver feel uncomfortable going over the speed limit, e.g. by making roads narrower, adding curves, etc.). You need both, but environmental calming is much more effective on the >95% of the populace that speeds because it "feels right," and not because they're sociopathically detached.

That's slowly changing, like in NYC with daylighting initiatives. But it takes a long time.

(European cities typically don't have this same shape of problem, since the physical layout of the city itself doesn't encourage speeding. So they get the environmental incentive structure already, and all they need to do is lower the speed limit to match.)

In Ontario a new speed zone is always signed with "BEGINS" below it, which is very helpful if you missed the last sign. I wish this was standard practice across Canada.

In much of Europe, including the UK, they have the concept of standardised "national" speed limits, which vary depending on the road type and which you are expected to know. When a road returns to the national speed limit, the sign is a white circle with a slash through it, indicating that there are no more local speed limits and the national speed limit is in effect.

I wonder if speed control of 50 to 30 km/h makes journeys faster in a city where you will hit traffic and traffic lights anyway. More consistent speeds, less braking.