South Australians seem to be leaving their bicycles at home and opting to drive to work, with a new survey pointing to a big drop in people choosing to hop on a bike.

The latest National Cycling Participation Survey has found 14 per cent of South Australians cycle each week, down 20 per cent from six years ago.

Nearly 300,000 people said they had jumped on a bike at least one day a week in the 2011 survey, compared with 239,000 when asked this year.

It has prompted calls for more bike infrastructure to turn the figures around.

"We do have a significant lack of infrastructure," Bike SA's Christian Haag said.

"While we've got plenty of bike lanes with a white painted line we know that when governments invest in good separated cycling it really encourages those people who want to ride to get out.

"That can really transform how our citizens move around the city."

The survey results have surprised Mr Haag.

"We were still seeing very robust bicycle sales through that period so people certainly are still continuing to purchase bikes," he said.

"So access to a bike is not really such an issue."

Bike SA wants better infrastructure to ensure South Australia is a safer place for cyclists. ( ABC News: Malcolm Sutton )

So are we becoming lazy or are there other reasons for most of us choosing a car over two wheels?

"In those areas where local governments are investing people are actually starting to use that infrastructure," he said.

"We are seeing greater cycling rates particularly in the CBD because clearly the City of Adelaide [council] is investing more.

"I think that's a lesson for other councils that if you invest, people will ride."

Transport Minister Stephen Mullighan conceded more needed to be done to attract cyclists on to the road.

"That's why the Government's investing tens of millions of dollars on improving cycling infrastructure across metropolitan Adelaide," he said.

"We've partnered with the Adelaide City Council to provide protected dedicated corridors running east-west and north-south in the CBD.

"We've also been investing to ensure that our train lines have cycleways alongside them."

The State Government is aiming to have 600,000 riders on the roads by 2020.