I wrote the blog below based on my experience of researching children and planning.
One particularly important issue I've found is that planners are more aware of the need to involve children in the planning process than they are about what children require in a place. Participation in decision-making is one side of improving the lives of children, but ultimately, it is creating more child-friendly environments that will benefit them most in the here and now.
The most pressing issue at hand is the decline of children’s independent mobility (or license to roam) over the past two generations. Between 1970 and 2010 there was a 61% decline in the number of primary school children travelling home from school alone, and the freedom of UK children lags behind that in many other countries. Many factors are at play here, but matters such as high traffic volumes and unwelcome public spaces can be managed through good planning. Indeed, resources on creating child-friendly environments already exist.