Jack Aston, 55, appeared in the County Court on Thursday for a plea hearing after being found guilty by a jury of negligently causing serious injury to six passengers when he drove into the bridge in 2016.

The court was told the Ballarat resident and Gold Bus driver was confused, new to the job and on a new route when he crashed into the "unexpectedly low bridge".

But Judge Bill Stuart said drivers must be alert to the "vagaries and the ever-changing risks" in the course of everyday driving.

"Possibly the most damning evidence against him was the observation of one of the witnesses ... of the imminent collision," he said.

"She saw it, he didn't and I don't get that.

"He had 14 passengers on board and of whom six were seriously injured. They were literally, in so far as he was the driver, in his care."

Judge Stuart said it was an unusual case in that Aston wasn't speeding, alcohol affected or distracted by his phone, but he had formed an almost "tunnel vision focus" and a "criminal lack of attention".

Defence barrister Richard Edney argued the bridge, built in the 19th century, was an ongoing problem for VicRoads and Melbourne drivers.

Character witness, Gold Bus company director Donald McKenzie, told the court Aston was a "good man" and should have been given better warning about the route and the bridge.

The hearing continues.

Australian Associated Press