CARS should be banned from streets around schools and more road space given over to dedicated walkways and cycle lanes to encourage more children to walk to school.

Researchers said European-style "safe routes" with virtually no motor traffic were required to curb childhood obesity and reverse the long-running decline in pupils travelling to and from school on foot.

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They also pointed to the examples of Darlington, Peterborough and Worchester in England which cut road accidents and increased the number of children walking or cycling to school from two per cent to eight per cent after they took part in a programme to reduce car use.

Writing in the journal BMJ Sports Medicine, researchers from Edinburgh University's Physical Activity for Health Research Centre, Spokes Lothian Cycle Campaign, and Edinburgh Napier University's Transport Research Institute, called on politicians and planners to drop the "windscreen perspective" of prioritising cars.

They write: "Public investment in active travel is far below that on road building, while measure such as road tolls and charging are resisted, resulting in a road building environment that often feels to risky for walking or cycling."

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They note that the average travel distance has almost doubled since the mid-1980s to 3.7 miles because the local school is "no longer the default option", and that children have to be much older now than in the 1970s before they are allowed to walk to school alone.

They add: "Minimising a child's independent transport is associated with substantial loss of physical, mental and social health benefits.

"Further, habitual sedentary travel as a child normalises sedentary travel behaviour as an adult...children need safe routes to schools that promote and enhance health.

"This is a choice available to many children in some European countries."

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Lead author Professor Chris Oliver said these safe routes in countries such as Sweden had virtually no traffic because road space was prioritised for dedicated cycle lanes and pedestrian walkways rather than cars.

He said: "In both Holland and Sweden the children are significantly lighter and there's less obesity in those countries. Many things have contributed to obesity, but having a good active travel infrastructure is a good thing."

He added that it would take "many years of quite significant investment" to bring Scotland into line with nations such as Holland and Sweden where more than 10 per cent of the annual transport budget has been invested in cycling and walking infrastructure for decades.

The Scottish Government has doubled spending on active travel from £40m to £80m in 2018/19, equivalent to 10 per cent of the trunk roads budget for the first time, but most councils invest a far smaller share on local roads.

Prof Oliver also welcomed initiatives such as exclusion zones piloted in Edinburgh which banned motor traffic from streets around schools at set hours.

He said: "I think the infrastructure they have to ban cars from around schools is good. To a certain extent that does exist with the zigzag lines around schools - you'll get a fine if you park on those.

"But I think you should make more space for walking and cycling around schools and perhaps you might want to have exclusion zones covering a significant area."

However, Hugh Bladon, spokesman for the Alliance of British Drivers, said drivers were already treated like "pariahs" and dubbed the proposals "social engineering".

He said: "I don't see why motorists should be penalised because parents are too idle to walk to school with their children.

"Not all parents are working so one mother who's not working could walk children from the same neighbourhood if they all get together.

"Why are we being forced to not use our cars when it's a perfectly reasonable thing to do? Having said that I wouldn't encourage anyone to drive half a mile to school with their child - they should walk.

"It's because of the fact that people are sitting there and not taking enough exercise that we've got this nonsense about a sugar tax and all that absurdity. People are obese because they're not taking enough exercise."

A spokesman for the Scottish Government said they had invested £217m in active travel since 2011.

He added: “We are learning from other European neighbours, such as The Netherlands, on how best to build active and healthy communities.

"Our focus is on making our towns and cities safer and friendlier with more segregated infrastructure, and putting people and place before motorised vehicles.

“We also provide funding to Cycling Scotland for on-road cycle training to all P6/P7 pupils in Scotland. We have asked Cycling Scotland to focus on this policy area to show a significant increase in take-up by the end of 2019. 

"To compliment this training, we grant fund Sustrans to run its Safer Routes To Schools programme which builds safer infrastructure to and around schools to encourage more cycling to schools by both teachers and pupils.”