Can you really drive on those at high speeds, is it dangerous?
There's a few short blocks in NYC that are still cobblestone and even at 30mph it sucks.
Honestly on some roads, I'd argue that's a feature.
It's ridiculous when there is a wide, flat, straight asphalt road surface with a speed limit of 25mph. Build it out of cobblestones, and 25mph suddenly feels a lot faster!
The problem is that today's cobblestones are pale imitations of the old ones, and won't last nearly as long. There's a parking lot near me built about 5 years ago, and they tried to be decorative with part of it and made it from concrete shaped to look like cobblestones. Because of the grooves and surface treatment it is much weaker than standard concrete, and it's crumbling.
I'm with you on the speed reduction. An urban planner friend talks about how you're best motivating a speed limit by the environment (tighter road, bends, etc) rather than a literal limit and threat of fine.
But how would cyclists fare on cobblestones, especially if you were talking about suburban streets with kids playing, bikes going around, etc?
It's ridiculous when there is a wide, flat, straight asphalt road surface with a speed limit of 25mph. Build it out of cobblestones, and 25mph suddenly feels a lot faster!