More than 6,000 drivers have been caught speeding in 15 days on a stretch of motorway in Bristol.
Average speed cameras were installed on the M32 where work to replace the central reservation was being carried out.
Enforcement of the 40mph limit, introduced nearly three years ago, started on 12 April.
Avon and Somerset police's head of road safety described the figures as "shocking".
Speed restrictions were introduced in August 2014 after it was discovered the central reservation between junctions one and two of the M32 was badly corroded.
Highways England said the 40mph limit was needed to protect drivers and workmen repairing the barrier.
In total, 6,048 motorists were caught.
Chief inspector Kevan Rowlands, head of road safety, said: "The number of people caught speeding in just 15 days is shocking.
"Speeding can have fatal consequences. It endangers the lives of other road users and the lives of those working on the M32 improvements.
"We don't want to catch people speeding, we want people to obey the speed limits. I hope this statistic acts as a warning to others that this speed limit is being proactively enforced and makes them slow down."
A Highways England spokeswoman said the cameras were due to be removed by the end of May.
Earlier this week, tougher punishments for the most serious speeding offences came into force in England and Wales.
Under the new guidelines, the worst offenders can now face fines of between 125 and 175% of their weekly income.