Transport for London has launched its first campaign to get residents to ditch their cars and walk instead.

The poster and radio advertisements urge commuters and drivers doing the school run to ask "Why not walk it?" and take to their feet instead.

Transport for London's Adrian Bell said: "People often overestimate how long it takes to walk a short distance.

"Walking can be a great way to make short journeys and this advertising campaign highlights that.

"It's also great exercise, environmentally friendly, and a brilliant way to start or finish your day."

The campaign comes as research shows half the car journeys in outer London are less than two kilometres and take an average 25 minutes to walk.

TfL is investing £126million over the next three years on new pedestrian crossings, lowered kerbs and improved signage.