Cr Desmae Harrison put a motion requesting the report to February's council meeting, saying that this issue been on her agenda for many years because of the isolation that is caused when floods, landslips, fires or car accidents close the Dorrigo Mountain road.

"When the mountain road goes out, it affects the whole shire," she said, listing the difficulties it causes people commuting to and from work as well as vegetable growers and dairy farmers needing to get fresh produce out to meet their contracts.

"The big one that affects me emotionally is that I know of many people who travel from inland to the coast to have oncology and specialist treatments," she added. "We know that with oncology, if you miss a session your whole program is thrown out."

Supporting the motion, Cr Steve Jenkins noted that Coramba Rd/Eastern Dorrigo Way was not the only possibility.

"There is a second road that goes from near Megan down to Ulong which is actually a Forestry road. I understand it is in a better condition than MR120," he said.

Cr Harrison said she didn't mind which road was upgraded.

"I'm not saying which route should be used - we do have two routes there.

"When it was investigated before, it was found that the route that goes through Forestry land was the best because it's wider and more stable. That was going to cost $20 million just to do that section then.

"I believe on both roads, council only own or maintain about six kilometres of dirt road before you get to the boundaries. There's only a small distance that concerns us."

Cr King said the upgrade would be complex, given that the roads span two shires and need expensive rehabilitation work. "The state government would have to make a decision to support it," he said.

"What I'm asking is that investigations start at council level to get the ball rolling," Cr Harrison said. "The report will come back to council but I feel the state and federal government will have to step up to the mark and help with this one."

General Manager Liz Jeremy said in the past council had advocated strongly for an alternative route to be established.