The Green Party has urged the Government to act on a new report which says it should increase the cost of driving in a bid to promote more efficient alternatives.

The report, Managing Transport Challenges When Oil Prices Rise, was commissioned by the New Zealand Transport Agency, in response to spiralling fuel prices.

The price of 91 octane petrol has dropped from $2.19 in July to just under $2 now, but the report's authors expect it to rise to $2.80 by 2014, presenting an urgent risk to the economy.

The report says New Zealanders are heavily reliant on their cars, with 80 percent of the population travelling by car and just 4 percent by bus.

It calls for the Government to promote more efficient, cheaper alternatives such as public transport, walking and cycling.

To change behaviour it suggests shifting land transport spending away from new roads into maintaining existing ones and upgrades to public transport.

It also suggests reallocating more road space to bus and carpooling lanes -- using congestion to make car use less attractive.

Other measures recommended include increasing charges for carparking and congestion charging.

Although the measures might be unpopular they would lead to the same being spent on petrol in 20 years as is now, it says.

The report's recommendations are broadly in line with Green Party policy and co-leader Jeanette Fitzsimons today urged the Government to sit up and take notice.

"After four years of trying to get the current Government and the public to recognise this it's very encouraging to get a report written for our main transport agency saying the same thing," she told NZPA.

"The public has already voted with their feet and started leaving their cars at home. Public transport in Auckland and Wellington is bulging at the seams at peak hour.

"We simply don't have the services and the Government is still planning in its latest land transport to spend eight times as much on new roads as it does on public transport."

Ms Fitzsimons said the Government should dump plans to spend billions of dollars on the planned Waterview tunnel in Auckland and the Transmission Gully motorway north of Wellington and put the money into public transport upgrades.

The report was written by transport consultants from McCormick Rankin Cagney and academics from Auckland and Victoria Universities.