Cycling groups have hit out at Colin Barnett over comments yesterday that they should ride in single file to stay safe, rather than rely on proposed laws to protect them.

Asked about the Greens' proposed bike Bill, which would force cars to keep at least 1m between them and cyclists, the Premier said he did not think it was practical.

"It would force cars travelling in opposite directions closer to each other," Mr Barnett said.

"It might be a good idea if cyclists rode in single file. That would be a good start."

Bicycling WA chief executive Jeremey Murray said Mr Barnett did not understand the issues surrounding cycling.

"If he thinks riders riding two abreast is the biggest issue, then he's well off the mark," he said.

"The biggest issue is the lack of infrastructure."

WestCycle chief executive Clint Shaw said a 70-year-old cyclist who died recently was riding single-file.