Networks of traffic-free routes and segregated cycle lanes in Scotland’s towns and cities would prevent 4,000 premature deaths over a decade and save £364m a year, a new report claims.

Walking and cycling charity Sustrans says its research has revealed for the first time the full financial and health benefits of removing choking exhaust fumes from the environment.

And it suggests that creating new segregated cycle routes alongside busy roads could encourage more people to swap their cars for bikes – even though it accepts that cyclists on busy roads are subjected to higher exposure to noxious fumes than if they were sitting in a vehicle.

The charity argues that the health benefits of cycling outweigh the risks of breathing in polluted air.

Lethal exhaust fumes have been linked to degenerative brain disease such as Alzheimer’s and are known to increase the risks of heart attacks, cancer and strokes as well as worsen lung conditions such as asthma.

Sustrans says its Connect 2 project which led to the infamous “bridge to nowhere” over the M8 being finally completed to create a partly segregated cycle route from the city centre to Kelvingrove, is already providing almost £105,000 in air quality-related health benefits each year.

John Lauder, Sustrans Scotland National Director, said the report findings back up the Scottish Government’s decision to double the budget for walking and cycling.

“It has never been more important to reduce the number of motorised vehicles on our roads,” he added. "By providing a network of direct segregated routes along busier roads in addition to quieter routes will encourage more people to walk and ride a bike."

However Neil Greig, Policy & Research Director of IAM Road Smart, said segregated cycle facilities should not be at the expense of other road investment.

“Scottish drivers already fund a wide range of government activities through fuel duties and road tax,” he added. “Investment in cycling has an important part to play in the future transport mix but it must take its place alongside a long list of other mobility priorities competing for limited funds.”

Sustran’s Air Quality Benefits of Active Travel report found the UK economy could save £931m annually - £9bn over 10 years - from improved air quality if goals to increase walking and cycling in Scotland and England are met.

Hitting Scotland’s Cycling Action Plan’s target of 10 per cent of all journeys by bike would deliver £364m savings per year, it claimed. Cleaner air would could avoid nearly 4,000 premature deaths over a decade.

The findings follow research from Friends of the Earth Scotland earlier this year which claimed 2,500 Scots die prematurely annually because of polluted air.

It pinpointed Scotland’s worst streets – including Hope Street and Dumbarton Road in Glasgow, St John’s Road and Queensferry Road in Edinburgh, and Wellington Road and Union Street in Aberdeen - where researchers found high levels of Nitrogen Dioxide (NOx), mainly derived from diesel vehicles.

However according to Sustrans even a switch to electric vehicles will not reduce pollution from car tyres and brakes.

A Transport Scotland spokesman said the Scottish Government had a number of initiatives aimed to encourage more Scots to travel by foot and by bike.

He said: “We are committed to making cycling safer and more commonplace in Scotland and have pledged to double the active travel budget from £40 million to £80 million in the Programme for Government. Our focus will be on making our towns and cities safer and friendlier with more segregated infrastructure improvements to the public realm.”