Its only common sense
I really wonder about the intelligence of people who try to control everything in their environment to the smallest degree. Teach your kids to be safe, don't try and make everything safe, the latter course does not and cannot work.
Roads are dangerous because cars use them. I taught all my kids that roads, car parks, driveways and any part of the world used by cars are dangerous and are never to be played on, nor strolled on carelessly. As well as this they were taught to look around before attempting a crossing. Before they were old enough to understand this, they were accompanied by and adult in public spaces. This was not foolproof, but then neither is trying to protect our kids by restricting car access on local roads.
Anyone driving a car is dangerous, no matter at what speed. If you drive a car you are part of the problem and pointing fingers at those other "bad" people is not going to absolve you from blame. Nor will it protect your kids if you say some areas of road are safe to play on, or they can forget about simple road safety rules because they consider a particular stretch of road is safer than others.
Consider that many people are hurt and killed in driveways and car parks. The last kilometer of road before you get home is one of the most dangerous stretches of road on your journey. Lastly if you want to see bad driving, go and visit a local school in the morning, the mothers dropping their precious kids off are totally focussed on talking to their own kids, as a result a lot of them are a menace to other drivers and any other pedestrians.
If you do succeed and make your area of the road safe, what will happen to your kids when they go somewhere where the road is not safe? What happens when the road is not as safe as you had thought and your kids are playing or strolling on the road? One correspondent has already seen this and commented. I suggest he undergo an anger management course before he hurts someone and his kids have to spend a few years without a father because he is in jail.
Lastly, chicanes, speed humps and road closures are adding to green house gases and harmful chemicals in the atmosphere that are mitted by cars, they interfere with emergency vehicles (that extra 5 minutes can be crucial to an ambulance or fire engine), and speed humps in particular can cause discomfort to people with spinal injuries and other painful conditions.