Nowadays, in most districts, you are not permitted to walk to school...you have to take the bus....too much fear of lawsuits if the little one gets hit by a car or something.
I had the option of taking the bus in my last couple of years of high school...I chose to walk. Friend of mine would always ride -- I got to school long before her bus did. :)
If my memory serves me correctly, there are only a couple of states that have any physical education requirements for school children. Illinois is one of them.