Greens Infrastructure spokesman Tim Morris said it was clear that stronger measures needed to be taken to tackle dangerous driving.

``Tasmania Police have made it clear that speed has been a consistent contributing factor in our road toll and high crash rate,'' Mr Morris said.

However, to get the trial up and running, Mr Morris would need Infrastructure Minister David O'Byrne to write to the Road Safety Advisory Council.

In the past Mr O'Byrne has not supported the idea and has said the advisory council would not either.

Road Safety Advisory Council chairman Jim Cox said that if the council received a request from the Minister, they would look at it.

Mr Cox said it was his opinion that drivers took more care during busy holiday times, and he would be more interested in a policy that was beneficial all year round.

Mr Morris said if a negative response was received from the advisory council, the only other mechanism would be to refer the matter to a parliamentary inquiry.

``A double demerit trial would cost almost nothing to implement, and the evidence suggests that it could be an effective public awareness tool for reducing the road toll,'' he said.

The proposed three-year trial would apply to selected weekends and public holidays and would target speeding and other dangerous driving behaviour.

It would double the points lost, not the fine.

Once the trial was finished Tasmania Police could use discretion to target certain behaviour at certain times.

Currently double demerit point systems are used in Western Australia, Victoria and New South Wales to target busy road periods such as Christmas.

The offences targeted include speeding, drink and drug driving, seatbelt and mobile phone use, as well as other dangerous behaviour.