More than 4000 trucks across NSW have been checked by police and vehicle inspectors less than a day into a surprise operation cracking down on "cowboy" drivers and "ratbag" operators.
Police say it's Australia's largest ever heavy vehicle compliance operation which is in direct response to a spate of fatal crashes over 48 hours in mid-January that claimed fives lives on NSW's roads.
Assistant Commissioner Michael Corboy said Operation Rolling Thunder was established very quickly but was methodically planned.
"We've found major defects; we've found unlicensed truck drivers but it's early stages yet," Mr Corboy told reporters in Sydney on Thursday.
As of 6.30pm on Thursday more than 300 defect notices had been issued and more than 20 drivers tested positive for drugs.
"Some people get into the trucking industry because they think they can make a quick buck, they push their drivers too hard, they run poor companies, they don't keep fatigue records and they're just in it for the money," Mr Corboy said.
"They're making their drivers drive fatigued, in some cases making them take amphetamines to stay awake, which is a complete recipe for disaster."
Mr Corboy told media the deaths of two teenagers, killed on January 16 when a semi-trailer ploughed into cars at roadworks near Dubbo, "pretty well moved me" and were the "catalyst" behind the crackdown.
The young couple, both aged 19, were among five people killed in heavy vehicle accidents in a horror 48-hours on NSW's roads in mid-January.
In the year to September 2017, the number of people killed in truck crashes on NSW roads jumped 86 per cent.
However the Transport Workers' Union of NSW said the operation doesn't do enough to end truck related road deaths.
"Truck drivers work under immense pressure with no option but to keep moving, while those forcing them to do this suffer no consequences," TWU NSW secretary Richard Olsen said in a statement on Thursday.
"As long as the NSW government continues to treat only the symptoms while ignoring the cause, truck-related deaths on our roads will continue."
Operation Rolling Thunder, which is carried out in conjunction with officers from Victoria, Queensland, the ACT and South Australia over 24-hours, aims to check every truck and heavy vehicle travelling in, through and out of NSW.
More than 450 police and vehicle inspectors from NSW Roads and Maritime Services (RMS) are involved.
Drivers are being checked for drugs, alcohol and fatigue while vehicles are being checked for roadworthiness.
RMS director of compliance Roger Weeks says the operation will rid NSW roads of shonky operators who are giving the trucking industry a bad name.
"We got a really clear message from those responsible companies and those professional truck drivers (in the) industry... telling us that they want us to get rid of the cowboys," Mr Weeks told AAP.
"They want the ratbag element out of their industry because they know it's those folk who are giving their whole industry a bad name, so that's who's in our sights."
