[bluescrn]

Instead, there's a push to reduce limits ever closer to zero.

30mph was close to the sweet spot and had been for decades. Or it would have been with a reasonable level of enforcement.

But as the ideological and/or climate-driven war on cars ramped up there's been a big push to reduce ever-more areas to 20mph, which is just too slow, especially when deployed widely/indiscriminately as it has been in Wales. (Used very sparingly, e.g. outside schools, 20mph limits were a good 'take particular care' signal to motorists - but that effect is lost when they're widespread)

Is it really about safety or is it about 'fuck cars'?

[Xylakant]

If you look at outcomes, 50km/h (30mph) is much less safe than 30km/h (20mph). If you look at the physics, that’s not surprising - stopping distances increase super linear. At the point where a 30km/h car would have come to a stop, a 50km/h car still impacts with 30km/h.

On the other hand, average speeds in populated areas usually are way lower than 30km/h, so lowering the top speed to 30km has negligible effect on travel times.

If you consider 50km/h the sweet spot, you prioritize vehicle speed over the very real risk of bodily harm for all other traffic participants.

[Dylan16807]

> At the point where a 30km/h car would have come to a stop, a 50km/h car still impacts with 30km/h.

At that point it's barely superlinear. That means instead of dropping by 30kph it dropped 20kph.

Personally I'd focus more on how even a linear increase in stopping distance is a problem when pedestrians are around.

> On the other hand, average speeds in populated areas usually are way lower than 30km/h, so lowering the top speed to 30km has negligible effect on travel times.

Negligible speed impact also means negligible safety impact.

[Mawr]

> 30mph was close to the sweet spot and had been for decades.

For car drivers maybe. From the POV of a pedestrian, 30 mph is very fast.