Primary teachers could be encouraging their pupils to take up exercise as research reveals almost half of children walk to school each day.
The Office for National Statistics said around 48 per cent of children walked to school in 2008 compared with 62 per cent in 1991.
In the same period, the number of children being driven to school rose from 27 per cent to 43 per cent, the report on social trends found.
A spokesman for the Department of Children, Schools and Families said: "The latest annual school census and the National Travel Survey show car usage is starting to fall and walking to school beginning to rise again but we know there is more to do.
"Local authorities now have a duty to make it as easy as possible for all children to walk or cycle to school, or use public transport backed by the £140 million Travelling to School Initiative."
Primary teachers could encourage their pupils to be green and healthy by ditching the car during national Walk to School Week which runs from May 17-21 this year.