Spot checks on heavy goods vehicles on the A55 in north Wales found the majority breaking the law, say police.
A total of 35 out of 43 HGVs (80%) were found in breach of a range of laws from overloaded and defective vehicles to a driver without a valid licence.
The majority of offences on Tuesday were dealt with by fixed penalty notices and summonses with over £2,000 paid in fines, said North Wales Police.
Some vehicles were confiscated after drivers were found without insurance.
'Disregard the law'
The operation involved police, Customs and Excise officials and enforcement staff from the Vehicle and Operator Services Agency (VOSA).
Sgt Tony Gatley, who led the operation, said: "It is shocking and disappointing to think how many drivers have a complete disregard to not only their own safety but the safety of other road users.
"The number of offences detected during the operation shows how vital initiatives such as this are, as a number of companies and drivers continue to disregard the law."