The inner-ring, Cleveland suburb of Lakewood, Ohio (population 51,000) calls itself a "walking school district". Since Lakewod has never had school buses in its history, kids naturally grow up walking and biking to school.
Mornings and afternoons are a beehive of activity on the streets adjacent to schools as kids and parents flow to and from classrooms. You can feel the energy and the students are likely healthier, happier and more aware of their community for it. The freedom of being able to walk and socialize with friends is immeasurable.
According to city planner Bryce Sylvester, "Lakewood is the densest community between New York and Chicago" and strives to structure their city so that every child is in walking distance of their school. It's a fact that has also paid off financially as Lakewood City School District spokesperson Christine Gordillo estimates the policy saves them about one million dollars annually.