Sadiq Khan today began reversing the rules of the road in a radical bid to get Londoners out of their cars.

Traffic signals at key locations will be changed to have the green man on at most times – giving pedestrians the right of way over traffic.

The red man will only appear when the signals detect a vehicle approaching. The Mayor’s aim is to encourage a million extra walking trips a day and make London “the world’s most walkable city”.

However pedestrians today raised immediate concerns that cyclists would ignore the new rules, placing both in danger.

This is despite official statistics showing that cyclists are involved in less than four per cent of pedestrian road injuries in London, while cars are involved in 63 per cent.

The proposed reprioritisation of traffic signals is part of London’s first Walking Action Plan, published by the Mayor today.

It also aims to crack down on the school run by encouraging more than half of the capital’s children to walk to school.

The first five “green man authority” signals will initially be introduced at 10 sites where the change “would significantly benefit pedestrians, with very little detriment to traffic”, according to Transport for London.

These include three crossings in the Olympic park – between the Westfield shopping centre and the London Stadium – near the Shard at London Bridge station and near St Paul’s, to help thousands of people cross the “wobbly” Millennium bridge to and from Tate Modern. The changes will be introduced from the Autumn.

In addition, “Scoot” traffic signals that increase the amount of time to cross the road when large crowds are detected will be expanded from seven to a further 20 locations.

Helen Cansick, head of network performance for TfL, said: “We don’t want pedestrian crossings to be a barrier to people choosing to walk.”

The Walking Action Plan promises to deliver “more numerous and wider pedestrian crossings” and discouraging school run traffic with more 20mph zones, timed road closures and car-free days.

Will Norman, the Mayor’s walking and cycling commissioner, said: “Getting more Londoners to walk regularly is essential for the health and future prosperity of our city.

“We’re investing record amounts to make walking the safest, easiest and most enjoyable way of getting around. It will tackle the air pollution crisis and reduce congestion as London’s population continues to grow.”

TfL has responsibility for all traffic signals in the capital. Last year it reduced the waiting time for pedestrians at 200 sites close to schools, hospitals and Tube stations, meaning they have no more than 40 seconds to wait for the green man.

City Hall says people walking spend 40 per cent more money in local shops each month than those who drive.

The strategy says walking has been “undervalued” by transport planners but is still the most common way for Londoners to get around. There are six million walking trips a day in which people walk all the way to their destination.

It reported that 21 per cent of Londoners say too much traffic is a barrier to walking, and 14 per cent say traffic travelling too fast is what stops them walking more. Sixty-six per cent said they would walk more if routes were improved to give greater priority to pedestrians.

Pedestrians account for more than a third of the 2,500 people killed or seriously injured on London’s roads each year, including 61 of the 116 fatalities in 2016.

TfL research suggests that Londoners make about 1.5 million short trips a day by car, bus or taxi that could be walked.

The Mayor’s wider vision is for 80 per cent of journeys to be made by foot, bike or public transport by 2041. The current rate is 63 per cent.

Mr Khan has set aside £2.2 billion to create “healthy streets” that promote “active travel” over polluting vehicles. For in 10 London children are overweight or obese.

Yvonne Doyle, London director of Public Health England, said: “The evidence shows that a brisk walk of just 10 minutes each day can go a long way to improving not just our physical health but also our mental health.”

A Walk Elephant initiative was launched last year at Elephant & Castle. Highbury Corner is currently being remodelled, and Old Street roundabout will follow next year.

At Swiss Cottage, where there has been furious opposition to a proposed cycle superhighway, work will start within weeks to remove the dangerous traffic gyratory.

An edited version of this story appears in today’s Evening Standard.