Or come to where I live in the midwestern united states and you see the same thing. I see kids as young as 7 years old riding bikes together on a bike path that has a very generous distance to the nearby road, and parents let them roam free.
Always remember: If you see a statistic about the US and think "wow, that sucks, the US must suck", remember, it's a very, very, very big country. The corollary to this is that if you see some small country with a really nice looking statistic, remember that the US probably has many, many, many places within it that also just as nice and share a similar statistic. If we were to lump the NL with all of Europe, I'm sure we could find some ugly looking statistics, and you would probably resent the idea of NL being lumped in with it.
Regression to the mean is a real phenomenon and I wish more people would understand it.