Since 2013 the length of the UK road network covered by permanent average-speed cameras has more than doubled, according to figures revealed by the BBC’s The One Show.
The cameras – which were introduced in Nottingham in 2000 – covered a total distance of 127 miles in 2013.
However, research conducted for the RAC Foundation found more than 130 miles of roads have since had the cameras installed on them, with 12 systems installed last year alone.
Average-speed cameras work differently to traditional speed cameras by recording the time it takes a vehicle to travel between two positions on the road.
The schemes range from less than a mile on Tower Bridge in London, to 99 miles on the A9 between Dunblane and Inverness.
According to Richard Owen, from Road Safety Analysis, which carried out the research, the cost of introducing the cameras had fallen in recent years.
He said: “The cost was now typically about £100,000 per mile, compared with about £1.5m per mile in the early 2000s.
“Some of the old fixed-speed cameras have been around for 25 years and they are based on 35mm film.
“They are coming to the end of their life so as they are replaced, they’re sometimes getting replaced with average-speed camera systems.”
In March, the House of Commons’ Transport Committee recommended further use of average-speed cameras on British roads, as they “are generally better received by motorists than traditional fixed-speed cameras”.
