The widow of a motorbike rider who was killed while driving from Canberra to the south coast on the weekend says Goulburn Mulwaree Council is to blame for her partner's death.

Jerrabomberra man James Hughes, 50, died on Sunday after losing control on the new Oallen Ford Bridge, near Nerriga.

He was thrown from his bike and fell into the Shoalhaven River.

The new Oallen Ford Bridge, on Oallen Ford Road, was opened to the public in September. ( ABC News )

His partner Melissa Pearce said there was a pothole on the bridge that he must have hit.

"He could not have avoided hitting the pothole, it was so large, if he could have avoided the pothole he would have, he was a very good motorcyclist and a very experienced rider," she said.

"At this stage what police have said to me is that they don't believe he was at fault, they don't believe he was speeding, they don't believe that there was a rider error or that James contributed at all."

On Sunday night, just hours after the crash scene was cleared, road workers were seen at the site.

The new Oallen Ford Bridge only opened on September 11, and according to local drivers, potholes started to appear just days later.

Following Mr Hughes death, many of those drivers took to social media to vent their frustration.

"Very shocked to see the condition of the road at the new bridge when we went through there on Friday, in fact the road from Nerriga to Oallen Ford is shocking," one Facebook user said.

"Funny how at lunchtime I drove over the bridge and there was no pot holes.... a little too late I'm afraid. Will email minister tomorrow," another said.

'I've lost my soul mate and I'm angry'

Goulburn Mayor Geoff Kettle released a brief statement on the accident, but was unable to provide an explanation.

Sorry, this video has expired Melissa Pearce says the death of her soulmate James Hughes was avoidable.

"As the accident is subject to a police investigation, it is inappropriate for council to comment," he said.

Mr Hughes' partner said it was hard for her to accept what had happened and she was furious with the authorities.

"I'm just devastated, I've lost my soul mate and I'm angry, this should not have happened," Ms Pearce said.

"James should be here at home with me ... he should not be dead.

"He's dead because there was a pothole in the road that wasn't fixed - it's not fair and it's not right."

Ms Pearce said Goulburn Mulwaree Council should have fixed the potholes earlier.

"Get your act together, I don't want anybody to have to go through what I'm going through," she said.

"It was avoidable, it should have been fixed - the problem was there weeks ago."

Ms Pearce said she was investigating her legal options and was also pushing for an inquest to be held.

"I really want a coronial inquest into why this happened and how it could have been prevented," she said.