More than 600 drivers were captured on camera exceeding the temporary speed limit of 50mph through roadworks at junction 46 of the M4 at Llangyfelach earlier this week.
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Travelling at inappropriate speeds under these circumstances is a prescription for disaster
"
John Rowling, Speed Camera Partnership
The top speed recorded was 86mph and the government agency which operates the speed cameras has warned that lives could be lost if motorists continue to ignore the limits.
The roadworks near the junction will be in place for two months and the Safety Camera Partnership (SCP) says it will be keeping a close watch on this particular stretch of the motorway.
John Rowling, project manager of the SCP, says speeding - not only results in a fine and points on a driving license - but also can kill.
He said: "We have serious concerns over the unacceptable speeds driven through the roadworks.
"The roadworks mean a temporary speed limit is necessary to ensure the safety of road users and operatives while lane width is restricted.
Deaths
"Travelling at inappropriate speeds under these circumstances is a prescription for disaster and can lead to serious consequences for other road users."
The partnership says fatal collisions along the M4 have more than doubled in the past three years.
The Safety Camera Partnership was set up to cover the South Wales Police area in April 2000.
It was extended to the Gwent and Dyfed Powys Police force areas in April this year.
The partnership is funded from the fines imposed on motorists.
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