The Labour Party is calling for an inquiry into whether low pay rates are causing truck drivers to break safety regulations.
Those who drive for some companies claim it is common for them to go without legally required breaks while driving for up to 100 hours a week.
In the past year, there were more than 50 deaths and 1,100 injuries in truck-related crashes.
Labour transport safety spokesperson Darien Fenton says there appears to be a link with impossible demands being put on owner-operators by large employers to deliver more for less.
Ms Fenton says she will push the Transport and Industrial Relations Select Committee to investigate whether the contract model is putting drivers and the public at risk.