My kids school do walk to school weeks and it's often encouraged in the school newsletters to walk your child/allow them to walk or cycle to and from school if possible. So far so good - child obesity, school run parking being a nightmare etc.
The only problem is as someone who does walk their kids to school they often make it spectacularly difficult! Think massive pieces of artwork being sent home that are difficult for any of us to carry especially when it's raining. And not allowing children to go to the toilet on the way out which means I frequently have to go out of my way to find somewhere with a toilet to stop off with my younger one on the way home as the walk is 30 mins.
Also being sent out from after school club in a t-shirt and shorts when there's snow on the ground so they end up having to get shoes off and put trousers on in the steeet. I've sent the dc back in before to get appropriately dressed but often they are sent out when the parent is seen on the path and the is door is closed behind them.
Aibu to think that if they want to encourage walking to and from school they shouldn't assume everyone is hopping straight into a nice warm car?