Speed cameras cut deaths ONWELSH road.
AVERAGE speed cameras have cut serious accidents on a major road by more than half.
The news comes as three councils in Wales prepare to use the same type of technology to enforce speed limits on local roads.
Average speed cameras check vehicle speeds over entire sections of road, rather than at individual locations.
In 2013 they were installed on the A465 Heads of the Valleys road between Hirwaun and Dowlais.
In the three-year period before the cameras were installed, 13 people were killed or seriously injured on that stretch of road.
In the most recent three-year period, five people were killed or seriously injured there - a reduction of 62%.
Official figures also reveal a dramatic drop in the number of collisions resulting in death or serious injury, from 11 in the baseline period to five in the period when cameras were operating.
Two people died as a result of accidents on the road in the three years after cameras were switched on - compared with four in the baseline period from April 2008 to March 2011.
The overall number of personal injury collisions also reduced but by a relatively modest 14% - suggesting that the main difference the cameras have made is to lessen the severity of accidents.
The safety figures may also have been affected by the Welsh Government's work to improve drainage at places along the A465.
The next Welsh road to be enforced by average speed cameras - starting next month - will be the A548 Sealand Road in Flintshire. Later this year the same type of enforcement will begin on the B4295 on the north side of Gower, between Gowerton and Penclawdd.
The Welsh Government recently awarded funding to Denbighshire council to procure and install average speed cameras along a road in deep countryside - the A5104 from Corwen to Rhydtalog.
Motoring group IAM Roadsmart welcomed the new figures. Tim Shallcross, the group's spokesman in Wales, often uses the A465 west of Dowlais and has noticed that many vehicles now travel at well under the 60mph limit.
He said average speed cameras were effective but deploying them was relatively expensive. "They're meant to be targeted at stretches of road which have high casualty rates. The Heads of the Valleys certainly fits into that category. It's one of the most dangerous roads in Wales."
He said it was sensible to install the technology on the three roads in Gower, Flintshire and Denbighshire if those roads had poor safety records.
Mike Bristow, of road safety charity Brake, said: "Speed limits exist for a reason - they save lives and it's great to see that we've seen a reduction in fatalities on the A465 since the introduction of average speed cameras.
"We urge drivers to stick within limits at all times, not just when they think they might be caught by a camera.
"However, Brake fully supports the police's use of every tool at their disposal to enforce limits, whether they be fixed, mobile or average speed cameras. By measuring an extended stretch of road, average speed cameras offer the advantage of discouraging drivers from only slowing down briefly for each camera, and then speeding off again and continuing to put lives at risk."
Teresa Healy of GoSafe, Wales' safety camera partnership, said average speed cameras had an excellent record for reducing traffic speed and collisions. "GoSafe was pleased to support the Welsh Government average speed camera scheme on the A465 Dowlais Top to Hirwaun. On this section of the A465, there has been a reduction in collisions, and on average vehicles are travelling under the speed limit of 60mph."
Asked about rolling out average speed cameras across the country, she said: "The relevant highways authority in Wales will be responsible for procuring and installing any fixed camera system. The decision and appropriateness will jointly be made with GoSafe, who will support the scheme with project management and agreement to enforce the schemes through their police partners."
In 2015 average speed cameras began to enforce the 50mph limit on the M4 at Port Talbot. The limit exists for environmental as well as safety reasons, where the road slices through residential areas.
Mr Shallcross commented: "The average speed check on the Port Talbot stretch of the M4 has encouraged far more speed-limit discipline than when people used to slow down for the one camera and ignored it [the 50mph limit] the rest of the time."
<B Deaths on the A465 Heads of the Valley road have fallen by 62% over the past three years