Police have accused trucking companies of endangering lives of drivers after finding almost half the heavy trucks stopped on South West roads last week had safety defects.
Traffic Sgt Gerard Murphy said police stopped 196 trucks on Forrest Highway between Mandurah and Harvey last week and issued 85 work orders.
Sgt Murphy said he was gobsmacked by reports that one trucking company was paying a monthly bonus to a transport manager for coming in under budget for vehicle maintenance.
"I'd hate to have to see those trucking companies sitting waiting to give evidence in a coroner's court, and for it to come out that they are scrimping on maintenance," he said.
"It shouldn't have to get to this."
Sgt Murphy said some truckies had approached police over problems with their trucks.
"In some cases we had truckies who were happy to see us and actually jumped out and showed us the problems, and told us they'd been telling the company to have it fixed," he said.
Sgt Murphy said the most common fault was bald tyres but there were also problems with cracked windscreens and reflector lights.
Australian Trucking Association communications manager Bill McKinley said that while most trucking operators complied with high safety standards, all companies were under increasing cost pressures.
"These companies need to be able to go and explain (this is) why they need to increase (freight) rates," he said. "Many trucking companies are on very low margins and are struggling to make ends meet."
Main Roads said more than 1000 heavy vehicles used Forrest Highway each day, making up about 11 per cent of total vehicle movements.
The safety report comes six months after truckie Paul Stewart Kershaw, 51, was jailed for five years for causing a crash in February last year that killed two men on Old Coast Road.
Australian Transport Workers Union WA assistant secretary Rick Burton said legislation passed in May meant big retailers would be forced to pay trucking companies a minimum or "safe" trucking rate for transporting their goods.
"At the moment there is a major problem with the big retailers putting pressure on the transport companies because they want produce delivered as soon as possible," he said.
"It's a cut-throat industry and some things have to be scrimped on - often it's wages and maintenance."