My vehicle almost idles at that speed! Hope it works out for them. You could probably go faster on a bike. You know what I'm going to do? Read the article. I'll be back with an edit if needed.
Edit: 80% of Amsterdam will have a speed limit of 30km/hr to increase safety and reduce noise.
Yeah, that's kinda the point. I'm a gear head through and through, and I support fewer cars in the city, it is not where they belong. I just spend 15 minutes driving around looking for a parking spot tonight. I wished I'd just been able to hop off a train.
Driving in the US is done on feeling alone. It doesn't matter what the limit is, it matters what speed you think feels best. Everyone's always doing that and if you're only going the speed limit you're probably obstructing the flow of traffic.