HALF of the lorries and vans stopped in a police operation were found to be defective or breaching the law in some way.
Forty vehicles were found to be at fault out of 80 stopped in checks on the M62 at Ainley Top in Huddersfield and on roads in Staincross, Dewsbury.
Chief Insp Gary Parker, head of the West Yorkshire police motorway unit, said roads had to be made safe.
More operations would take place during the year, he said.
Chief Insp Parker warned: "If drivers go out in defective vehicles, they will be subject to police attention."
Seven vehicles were immediately prohibited from using the road due to brake or tyre offences.
One was an abnormal load which was 10 tonnes over the legal limit and had numerous mechanical defects.
Drivers were told to take action over corrosion, suspension, brakes, steering and tyres.
Some drivers were warned for exceeding their hours behind the wheel, not taking rest breaks and speed limiter offences.
Four vehicles were overloaded or overweight by more than 10% and another two drivers were given verbal warnings for driving vehicles less than 10% overweight.