Tourists to the State are still expressing their horror and disgust at the high number of mutilated animal corpses they see.

The Parks and Wildlife Service estimates that more than one million vertebrate animals are killed each year on the State's roads and the number is increasing.

The cost of roadkill in property damage and human injuries is estimated at over $17.6 million.

A Roadkill Collective set up in 2000 to look at ways of reducing the toll is in recess.

The collective was a working group consisting of representatives of the Nature Conservation Branch of the Department of Primary Industries, Water and Environment, the Land, Transport and Planning Division, local government, Tourism Tasmania and the Tasmanian Environment Trust.

Its efforts culminated in a report released last year on the value of various techniques to reduce the wildlife toll.

Convenor of the collective, Margaret Steadman of the Tasmanian Environment Centre, said a handbook for roadkill issues was being prepared for use by the public, local government and road managers.

Parks and Wildlife officer Nick Mooney has done extensive research into roadkill and believes that road engineering solutions are futile.

The single most important reason for roadkill is road speed, he says.

"People go through these contortions to find engineering alternatives to people being more sensible and slowing down," he said.

"The problem is we're making roads faster at the same time as we're asking people to slow down."

The PWS estimates that brushtail possums, pademelon wallabies, bennetts wallabies and rabbits make up around 95 per cent of the total roadkill.

But many rare or threatened species are also killed, including eastern barred bandicoots, quolls, 1300 birds of prey such as the endangered wedge-tailed eagle killed each year and up to 5000 Tasmanian devils.

The PWS Nature Conservation branch says one of the main reasons for the high incidence of Tasmanian roadkill compared to the mainland is the relative abundance of animals in Tasmania for the land area.

Another reason is that many of Tasmania's animals are most active at night and their colouring makes them difficult to see.

NCB management section manager Greg Hocking said that while tourists were shocked because they were unused to seeing such numbers of roadkill on their roads, he thought that Tasmanians had become hardened to the sight.

He said there was no easy solution and the issue required a strategic approach incorporating both driver education and road engineering solutions.

Research by the collective showed that ultrasonic whistles had no effect on wildlife or the incidence of roadkill.

Mr Hocking said the Department of Infrastructure Energy and Resources was implementing road changes recommended in the report such as canopy crossings, ditch management, underpasses and light-coloured road surfacing where practicable.

He said the department encourages local councils and the Department of Infrastructure Energy and Resources to have the corpses removed as a priority.

"This not only reduces the eyesore but helps reduce secondary kills of animals such as ... devils and quolls that come on to the road to feed on them," he said.

Roadkill was an aesthetic issue, an animal welfare issue, a conservation issue and a tourism issue.

He said the most important measures in combating roadkill were: reducing speed and being aware of potential "hotspots" where animals are likely to be trapped against steep cuttings, crossing the road or feeding beside the road.

ROADKILL FACTORS:

¤ Fast roads.

¤ High speeds

¤ Wildlife-rich areas - roads between forests or grasslands or near watering places. ¤ Seasons - more animals around in summer and after droughts.

¤ Time of day - more animals killed at night.

¤ Type of weather - more animals about on calm, still evenings during darker moons than on bright moonlit nights and in inclement weather.

¤ Carcases remaining on roads - raptors and carrion eaters at risk.

¤ Road alignment - animals can become trapped against steep banks, inside of corners.