A class action by families and victims of a horror bus crash that killed 10 people is likely to be expanded after the NSW government flagged it is likely to sue the company involved.
Driver Brett Andrew Button, 60, was sentenced in September to a maximum of 32 years behind bars over the crash in the NSW Hunter region in June 2023.
He was behind the wheel of the bus carrying 35 wedding guests when he lost control of the vehicle in a roundabout at Greta.
The bus crashed into a guard rail and ended up on its side, killing 10 people and injuring 25 others in the process.
Survivors and family members of those who died have launched a class action against Transport for NSW alleging design failings in the roundabout.
The case came before the NSW Supreme Court for the first time on Friday, when Justice Peter Garling asked whether the state agency would file a cross-claim against Linq Buslines, the registered owner of the vehicle that Button was driving.
"I suspect that is highly likely, Your Honour," Transport for NSW's lawyer Brian Moroney said.
Justice Garling pointed out for Transport for NSW to defend the case completely, it would have to prove Button's driving was the sole cause of the accident.
"If the plaintiffs can establish five per cent negligence on your client's part, it doesn't matter to them about the other 95 per cent," he told Mr Moroney.
Button was driving while impaired by an opioid painkiller, taking 350mg of tramadol on the day of the crash despite doctors telling him the daily maximum dose was 200mg.
Barrister David O'Dowd said the class action would remain focused on suing Transport for NSW and would not include Linq in its claims.
The class action is led by Adam Bray, whose son Zach was killed in the crash.
It includes passengers who were physically injured in the crash or suffered mental harm due to the crash.
Court documents include allegations the interchange where the crash took place had numerous design flaws, such as being elliptical instead of round.
It also featured guard rails instead of run-off areas and a gutter that was a "tripping risk" for larger vehicles.
The speed limit through the roundabout was also allegedly too high.
Mr Moroney said Transport for NSW was busy compiling all design documents behind the Greta interchange before it filed a defence.
He said there was also an ongoing inquiry by the Office of Transport Safety Investigations but its report was yet to be published.
A defence and the potential cross-claim against Linq is expected to be filed by January 17.
The class action will return to court on February 7.
