It has been 12 months since Holbrook became the last town on the 800-kilometre route between Sydney and Melbourne to have two lanes running through its centre.

When Holbrook became the 49th and final bypass along the Hume, there were fears the town of 1200 people would struggle to survive.

Holbrook was not wiped off the map, but Greater Hume mayor Heather Wilton said the town lost economically valuable fly-in construction workers, who were diverted elsewhere after project completion.

"There has been a drop off in trade and discretionary spending," she said.

"We had a bit of a false economy for a while. Those fellows were spending money that wasn't previously being spent in the town.

"We're really back to our bare bones now."

Helen Thompson, the owner of Holbrook's legendary Submarine Cafe, agreed, and said the town had felt the impact of the bypass.

"We've missed out on the spontaneous trade," she said.

"I could guess by about 15 per cent."

Councillor Wilton said she was optimistic about Holbrook's future with tourism, and pointed to distinct attractions like the yellow submarine.

Cr Wilton said HMAS Otway, which was "yarn-bombed" as a tribute to The Beatles, significantly boosted tourism numbers.

"It really drew attention to Holbrook," she said.

"We are very well located for breaks in people's trips. For the travelling public, we are the place to be."

Ms Thompson said people who knew Holbrook - the regular visitors - would keep coming.

"People who have been coming for 10 or so years will keep coming because they know the town," she said.

"I could not believe the distance people travelled to see that yellow submarine."

Robin Scobie, a volunteer at craft shop Grimwood's on the old highway, is frustrated businesses on the northern end of town are soaking up tourism dollars - and leaving none for the southern side.

"People still come to look at the sub as an oddity - but that is there only stop, they don't stop anywhere else," she said.

"I think all of us are really feeling the pinch."