TRANSPORT minister Keith Brown has come under attack for the decision to install average speed cameras on Scotland's most dangerous road.

Mr Brown announced plans to spend £2.5 million on installing the cameras on the A9 between Dunblane and Inverness.

But Highland MP Danny Alexander has written to Mr Brown asking him to provide evidence that the scheme will help prevent accidents.

Mr Alexander has also called on the Scottish Government to bring forward plans to dual the A9.

The Scottish Government has pledged to dual the A9 in the long term but Mr Brown said the average speed cameras should lead to more immediate improvements.

Mr Alexander, MP for Inverness, Nairn, Badenoch & Strathspey, said:"It is clear the high speeds are a significant factor in some of the horrific accidents.

"But it is also clear some of the dangerous driving on display is caused by frustrated drivers caught in very long queues behind lorries and tankers."

A Scottish Government spokeswoman said: "Dualling the A9 is complex and challenging and involves detailed planning and consultation process before construction can begin."

The Government said a safety group had agreed an average speed camera system would have a positive effect on road safety.