As a study suggests that the health of pupils is suffering as more parents drive children to school, Wheatfields Junior School, in St Albans, Hertfordshire, has pioneered a radical, pollution-free transport system that runs on pupil power.

A trailer carries the luggage home

The "walking bus" devised by the school combines the health benefits of walking and the safety of a supervised journey home.

At the end of school, two parents act as driver and conductor on an imaginary 'bus ride', with the children walking home together as a group. School bags are carried on a pupil-pulled trailer.

The children, who walk in line wearing reflector jackets, are taken on a route that passes all their homes, addressing anxieties about safety that have caused many parents to use their cars.

Parents have peace of mind that their children are being walked home, said 'bus driver' Coreen King

"It's safer for children and there's peace of mind for parents that someone is walking their children to school," said Coreen King, parent and volunteer bus driver.

As a further incentive, loyalty stickers are given to regular users of the walking bus which can be exchanged at the school for books.

A fifth of all morning rush-hour car journeys in term time are believed to be parents taking children to school.