Cars kill 120 deer on the Ashridge Estate every year

The devices, on posts near the road, are triggered by passing traffic and give off a whistle to startle deer and prevent them wandering on to the road.

At the same time, an interactive sign that can be set off by the animals will warn drivers to slow down.

The scheme is being piloted on the National Trust Ashridge Estate where cars kill 120 deer every year.

'Serious injury'

Involved in the project on the estate at Ringshall, Berkhamsted, is the National Trust, the Chilterns Conservation Board and Herts, Beds and Bucks county councils.

"Accidents involving deer are at their highest between October and December, which is why we're implementing this equipment now," said Stuart Pile of Herts County Council.

"Accidents are often caused by a driver swerving to avoid a deer and veering in to the path of an on-coming vehicle, causing a major collision which can result in serious injury and even death."

The council has been working with the Deer Collisions Project leader, Dr Jochen Langbein, on the project.

Results monitored

Dr Langbein said: "It is important that we are aware of all collisions involving deer.

"The only way that we can record all incidents is for the people involved to tell us about it and urge all members of the public to do so."

The results of the project will be monitored and, if successful, will be used in other parts of the country.