THE CYCLING network in Oxford would need to be more than twice its current size to get the maximum health benefits, a leading academic has said.

Oxford University researcher Christian Brand says the roughly 100km of dedicated cycle lanes could be more than doubled before the returns start to tail off.

Dr Brand was speaking after publishing a study which found the ideal peak proportion of cyclists in any city: 25 per cent.

He and his colleagues analysed data for cycle network length, proportion of people who cycle and premature deaths across 167 European cities.

The found, not surprisingly, that cycling always helps cut the number of premature deaths and that more cycle networks generally encourage more people to cycle.

However they also found that those general links were only true up to the point a city has got 25 per cent of its commuters on bikes.

After that point, many cities can keep increasing their cycle network but the number of new cyclists tends to tail off, suggesting there is an average maximum number of people in any city who will ever be persuaded to get on their bike: a quarter of the population.

The current proportion of people who regularly cycle in Oxford – mostly commuters and students – is about 18 per cent – seven per cent below target, Dr Brand said.

His team's analysis of the links between cycling and health suggest that if seven per cent more commuters could be persuaded to bike to work, seven premature deaths could be prevented each year.

This is entirely down to the health benefits of cycling.

What's more, according to UK government analysis, this could save the economy £4m per person – some £28m a year – in NHS bills for poor health in later life and in the turnover lost to the economy through any person's early death.

Dr Brand of the Transport Studies Unit said: "Our paper suggests that if Oxford can improve and build a dedicated cycling network and achieve 25 per cent bicycle share, then premature mortality would be reduced amongst those who use the network."

Oxfordshire County Council, the highways authority, said it was working on just that.

Spokesman Owen Morton said: “We want to see more and more people cycle safely, which is why we are committed to doing what we can to improve safety and access for cycling.

“We firmly believe that continuing to invest in safer environments for cyclists and making better use of our roads is the way to go, as demonstrated through the improvements we are delivering in East Oxford as part of the Access to Headington project.

"This is something Oxfordshire County Council has been doing for some time and will continue to do in Oxford and Oxfordshire."

Across Oxfordshire the number of regular cyclists rose from just over 8,000 in the year 2000 to about 13,000 in 2016.

The number of adult cyclists involved in serious and fatal collisions over the same period crept up steadily from under 50 each year to more than 60.

However the number of children being involved in minor accidents each year plummeted over the same time from about 56 a year to about 20.

Latest figures from Public Health England estimate that 276 deaths across Oxfordshire could be attributed to long-term exposure to air pollution, including NO2, in 2014.

The NHS says regular cycling can reduce the risk of chronic illnesses such as heart disease, type 2 diabetes and stroke, and boost mood and keep weight under control.

However, for health benefits, it says adults should do at least two-and-a-half hours of moderate-intensity cycling each week.

The NHS recommends cycling to work on a few days each week as the perfect amount.