The Transport Workers' Union wants Chain of Responsibility changes, as the trial of a truck driver over the deaths of two people begins.

Truck driver Shane Day – a former Cootes employee - faces charges in a Sydney court after his oil tanker turned over and caught fire at Mona Vale in 2013, part of a horrific incident that claimed several lives.

An audit of Cootes trucks in the wake of the crash found hundreds had potentially disastrous defects across the fleet, leading it to be grounded and the company fined $500,000.

“What we are seeing in today's case, as has occurred in many cases before, is that the driver is carrying the entire burden for an industry in crisis,” TWU National Secretary Tony Sheldon says.

“Neither the transport company nor the client whose fuel he was carrying are in the dock over corners they cut which led to safety risks.

“If someone is killed because a vehicle is not maintained properly or because the driver is pushed to work long hours then justice can only be served when those responsible are held to account,” Sheldon added.

“Responsibility for carnage on our roads needs to go all the way up the supply chain. Prosecutors, governments and regulators must look at the chain of responsibility laws and ensure they are capable of holding those ultimately to blame for the daily tragedies to account.”