In Netherland, the speed limit in cities used to be 50, and even in the 1980s, people were complaining that that was too fast. Most residential streets have been 30 (or less; the street I grew up in had a limit of 5 or 10 km/h) for some time, and Amsterdam recently made it the default for all streets with only exceptions for the biggest thoroughfares. They've also experimented with closing some of those thoroughfares.
Cars are bad for cities. It's a simple fact. The big advantage of cities is that everything is within walking or cycling distance, and the density is perfect for dense public transport. The only use for cars is to get out of the city.
Low speed limits make cars safer, but they also encourage safer forms of transportation. It's great to see this insight take hold in more countries.