By Alan Whitehouse
BBC transport correspondent
It is claimed speed cameras save lives
The number of speed cameras on West Yorkshire's roads is to be doubled over the next two years.
A list of accident blackspots has been drawn up where it is hoped installing cameras will force drivers to stick to the speed limit.
At the moment there are 68 cameras in the county. This will increase to 136.
One route that is set to get new cameras is the A644 Huddersfield to Dewsbury road at Mirfield.
Over the last three years 25 people have been killed or seriously injured there, so six new cameras are being put in.
The West Yorkshire Casualty Reduction Partnership says there is strong evidence that cameras reduce accidents.
In Thornton Road in Bradford, four people were killed and 29 hurt in just 12 months before cameras were put up.
In 2002, after their installation, there were only four crashes causing 12 slight injuries.
More cameras have already gone live on the Elland bypass and extra are to follow.
Alan Whitehouse will be taking part in a live webchat on BBCi Leeds and BBCi West Yorkshire between 1900 BST and 1940 BST on Thursday.