A police safety blitz in south-west WA has found almost half of 196 heavy trucks stopped on the Forrest Highway had safety defects.


According to an ABC report the defects included faulty seat-belts, bald tyres and cracked windscreens.


Traffic sergeant Gerard Murphy was reported as saying that some trucking companies are putting the lives of drivers at risk by scrimping on maintenance costs.


"One of the companies' truck drivers said their transport manager, who was in charge of fleet maintenance, was basically being paid a monthly budget for coming under budget," he said.


"When you're looking at vehicles that are 25 or 30 tonnes pulling fairly large trailers, to have bald tyres, suspension that's not working, brakes that aren't operating correctly, seatbelts that aren't working properly, it can be very concerning to the motorists who have to drive on the same road as them," he said.