[anonymousDan]

Yeah I moved a short distance in London to an area that is all 20mph and for me the most noticeable change is the reduction in noise levels (the limits in the previous area were generally 30mph). The new area feels so much more peaceful. It surprised me how much difference a 10mph drop makes.

[matsemann]

It's also surprising how much safer that little speed change is for pedestrians/cyclists if they were to get hit.

https://www.nullvisjonen-agder.no/images/grafikk/dodsrisiko-...

Speed in km/h vs death rate. From about 10% death (90% survival) at 30 km/h (~18mph) to about 80% death (only 20% survival!) at 50 km/h (~31 mph)

[MandieD]

A 30 km/h car is also a lot less likely than a 50 km/h one to hit a cyclist or pedestrian in the first place - far shorter braking distance, and longer time for the slower mover to spot and avoid them.

Also, as someone who is both a cyclist and a driver, there’s a bit less urgency and frustration to pass a 15-20 km/h bicycle when you’re only allowed to do 30 anyway than when the limit is 50.

[mcv]

I think this is by far the biggest reason for the preference for 30 km/h. Reduced noise and pollution are certainly nice, but killing far less people is huge.

[MandieD]

It also gets people like me who are scared to ride a bike on the 50 km/h street to reconsider how they’re going to run to the grocery store to pick up stuff that can fit in a backpack, or to daycare.

I default to doing both on bike, because the convenience outweighs any safety concerns, now that my neighborhood (suburban Nürnberg) is all 30 km/h.

And my kid will be able to be more independent at age 10 than I was at 15 growing up in car-bound Texas.

[anonymousDan]

Sure, as a sometime cyclist I am not discounting that as a reason. I made the comment above as I found it was something that perhaps isn't mentioned as much but really does give an immediate quality of life improvement.

[pakitan]

Why not reduce speed to 10km/h then? Even fewer people will be killed! This is the covid logic all over again. Let's lock everyone in their homes, we can't afford to have old people dying!

Also, no, ICE cars generally don't pollute less at 30km/h, compared to 50km/h. Engine does the same work, just at lower gear.

[mcv]

> Why not reduce speed to 10km/h then? Even fewer people will be killed!

It depends on how the street is used. There are places where maximum speed is 10 km/h. I grew up in the street like that: a "woonerf", a residential area where the street is explicitly meant for playing children, and cars have to go at pedestrian speeds of 5 or 10 km/h. The goal these is to not lock up kids in their homes, but encourage them to play outside, which is great. These were fairly new but popular in the 1980s and late 1970s, but not so common anymore, sadly.

30 km/h is roughly the speed bicycle of bicycles and similar vehicles. Not suitable for playing kids, but more suitable for mixed through traffic. Driving through an entire city at 10 km/h would be as tedious as walking that entire distance, but 30 km/h is very doable.

[Vinnl]

Doesn't really affect your point, but AFAIK the maximum speed on a woonerf is 15 km/h.

[phanimahesh]

Let's make it so that cars don't have to dictate peoples movements so that people won't feel personally attacked by regulations slowing card around pedestrians, kids, and elderly in residential areas.

[matsemann]

Did you see the graph in my comment? There's a steep curve beginning a bit over 30 km/h. Hence great impact per km/h reduction at those higher speeds. Not as much when going even even lower. Most people don't think in extremes, and are actually capable to think of the various tradeoffs. No need to be so hyperbolic..

I'd like some streets to be 20 km/h as well, though. But that is because those streets should be for pedestrians / kids / those living there, and not for traffic.

[pakitan]

I saw the graph. It's probably crap, given that there is 5% death rate at 0km/h but let's take it at face value and let's say we implement 30km/h limit. Then there will inevitably be people claiming "death rate can be reduced by another 40% if we were just responsible enough to reduce the limit even further, to 10km/h". That's not hyperbole, that's exactly the way events unfolded near the end of the covid epidemic. Under the "every life is important" slogan, there was massive strain imposed on everyone, just to have a tiny % of old people die next year instead of this one.

Of course there should be 10 or 20km/h limits on certain streets, no one is arguing about that. We're talking about city-wide limits. Here, if I was driving at 30km/h on a main city road, I'd be lynched and rightfully so.

[matsemann]

At ~0km/h kids are unfortunately still dying, mainly being backed over by their own family.

The rest of your argument is basically a slippery slope fallacy and not even close to what's happening in any urban planning discussion I've ever been a part of. And I'm on the board of an organization discussing these things.

[michaelhoney]

your first paragraph is a needless exaggeration, and your second is demonstrably untrue. Calm down and recognise that this change will result in quieter, safer streets. There’s nothing to be threatened by.

[Muromec]

Ban ICE cars altogether while we are on it!

https://www.amsterdam.nl/verkeer-vervoer/milieuzone-amsterda...

[ricardobayes]

I wish they would actually explain some of the decisions - I think everyone would understand and even perhaps advocate and wish for changes like this, instead of immediate pushback.

Even in the most transparent of places, I don't really see decisionmakers explaining their decisions.

[pjc50]

No they wouldn't. We're deep into post-evidence politics.

In all these cases the decisions have been explained, in the normal place, but that's too boring to share on social media so nobody hears it.

[nvm0n2]

The decisions haven't really been explained by the standards of explanation you might expect for such a move, at least not everywhere.

In Wales the official explanation is: Welsh ministers said a 20mph (32km/h) limit would reduce deaths and noise and encourage people to walk or cycle [1]. Drakeford elaborated by saying "It's going to take you a minute longer to make your journey, and we will save 10 people's lives in Wales every year as a result of that one minute contribution - it doesn't seem an unfair bargain".

This explanation is nonsensical:

1. It could just as well apply to a limit of 5mph, or 10mph, or banning cars completely. It explains the desire to lower the limit but not the choice of 20mph vs 30mph.

2. The claim is that it adds a "minute longer" to make your journey, a clearly confabulated number. Not all journeys are the same and lowering the speed limit nationally will clearly be a scaling factor to your journey time, not a constant minute regardless of distance.

3. The justification is a 100% subjective feeling that "it doesn't seem unfair". This isn't an explanation, just an emotion.

When politicians serve up gibberish explanations, people tend to split down the middle. One half will assume that politicians are just being really stupid. Others will say that nobody can be that stupid, so there must be some alternative agenda at work.

Certainly this looks to people like "post-evidence politics" albeit not in the way you probably imagine.

It doesn't help that these people are socialists who have a long history of presenting one explanation for their policies whilst actually having another. When they're in friendly territory they tend to talk about how much they strongly desired things like enforced equality of outcomes, degrowth and reducing CO2 emissions, but they never talk about pedestrian safety. So when they impose policies that will clearly have the effect of reducing growth and car usage, but justify it with some new cause they hardly talked about before, it doubles up suspicion again.

BTW the 20mph limit didn't appear in any manifesto. More people have now signed a petition against it than voted Labour in the first place. So they can't claim these policies are popular or democratic.

[1] https://www.bbc.com/news/uk-wales-66774379

[mcv]

Point 2 is nitpicking. Obviously every trip is different, but a reduction from 30 to 20 mph does not have nearly as big a difference on travel times as your proposal to reduce all the way to 10 or 5 would have.

Everything is a compromise. 30 mph was a bad compromise because it's a deadly speed that will kill people in a collision. 20 mph is significantly safer. Reducing further to 10 mph or even 5 mph would not have a significant further effect on safety in normal traffic conditions, but would have a significant impact on travel times if people have to drive at that speed for a significant part of their trip.

I think it's your complaints that are 100% subjective. There is evidence for these policies. Politicians rarely go into that evidence for public announcements because most people aren't that interested in the evidence, but that doesn't mean it doesn't exist. You're suggesting that politicians randomly pick some numbers out of the air just to upset people, but the opposite is true; you generally need an excessive amount of evidence to get politicians to do anything at all, especially when it even slightly inconvenience the oil and car lobby. I mean, look at the lack of action to mitigate climate change despite the excessive amounts of evidence.

[nvm0n2]

Your first paragraph contains a one sentence explanation they could have easily chosen and presented, but they didn't. That's the complaint.

> your proposal

I haven't made any proposals. My proposed alternative would be for the Welsh government to focus on much bigger problems that they may actually have a mandate for. The alternatives were just examples to illustrate the point. Ask yourself why 20 and not 25, if it helps.

> you generally need an excessive amount of evidence to get politicians to do anything

What an amazing country you must live in. For the schmucks like us in the rest of the world, we have the politician's fallacy. Something must be done, this is something, therefore it must be done. Evidence-based policy making is the exception not the norm :(

[timrichard]

Yup. Another data point from someone driving in Wales at the moment :

- People seem fixated on their speedometers rather than the road, which isn't great for safety.

- I'm spending way more time in third gear when I would have previously been in fourth, meaning the engine is revving higher, thus consuming more fuel, thus releasing more emissions.

- The rollout has been utterly chaotic. They first released an interactive map, which bore little resemblance to the changes to the speed signs on launch day, and councils are still tweaking the opt-out status of individual roads.

Personally, I think safety goals could have been met by building way more zebra crossings. In my experience, motorists do slow and stop for them, and they would have a natural traffic calming effect at the times when pedestrians need them the most. However, that wouldn't help with bullet point #2 on the Welsh Government website, which is to encourage more people to walk and cycle. Much of Wales is rural, and for those people a car is a necessity rather than a luxury. When I lived in London, many buses were every three minutes. Where I live at the moment, it's two a day on many routes. Regardless, if cycling and walking is the true agenda then they should have had the guts to be open about it. Instead, they hide it behind think-of-the-children, which mainly has big support from people who drive SUVs for the school run. Despite the fact their vehicles are much heavier, ride higher, and have an angular front that would be much worse for anyone (especially children) that they might collide with.

[taylodl]

I'm an American but I'm into British motorbikes so I watch guys like Stuart Fillingham on YouTube. It's predominantly a motorbiking channel but he talks a lot about local politics and he's been all over these laws and the Net Zero laws in general. You should check him out because if even half of what he says is true then you folks are about to get whacked upside the head!

[rsynnott]

> It could just as well apply to a limit of 5mph, or 10mph, or banning cars completely. It explains the desire to lower the limit but not the choice of 20mph vs 30mph.

Banning cars completely wouldn't be particularly practical. Death rate increases pretty dramatically after about 20mph/30kph. Do not let the perfect become the enemy of the good, here. 30kph in urban areas is about a sweet spot; it makes things a _lot_ safer but doesn't impact the utility of the cars that much.

[nvm0n2]

Fine, but none of that is how the policies are being justified, which is what the actual complaint is here. It's not that no justification can be conceived of.

You don't get to kvetch about how boringly logical and evidence-based the explanations are so it's just the prole's being stupid, when the people creating policy aren't justifying their policies with evidence or logic in the first place.