Douglas Shire Mayor Julia Leu says she is 'incredibly disappointed' with Main Roads' decision to approve traffic lights set be installed later this month in Mossman.

The project was given the green light following extended discussions between developer Town and Country, Cairns Regional Council and Main Roads over more than 12 months.

The new Douglas Shire Council entered discussions following deamalgamation in January but couldn't overturn the decision.

Cr Leu said the lights could create congestion in the town, blocking roads that intersect with Front Street.

"We don't believe that it necessarily is a safe option," she said.

"With the banking of traffic, including cane trucks, at peak times during school pick-up hours ... we think it could be worse."

But Main Roads said the developer's proposal complied with current regulations and that the developer had chosen to place the lights on Front Street.

"[Our] role, as a governance agency, is to assess the developer's access design based on our technical and safety guidelines," the spokesperson said.

"The developer is responsible for designing an access solution that enables motorists to enter and exit the upgraded property without adversely affecting traffic flow and road safety."

Mossman residents rallied to have the decision overturned, staging a protest in February.

Cr Leu said greater consultation with the community of less than 2,000 residents may have led to a better outcome.

"It's very clear that the community does not support traffic lights," she said.

"I think it's incredibly disappointing that the traffic issues weren't sorted out prior to the building commencing.

"Then we would have had a greater opportunity to influence that [process]."

When installed, Mossman will be home to the most northern set of traffic lights in Queensland.

The next nearest set will be at Clifton Beach, almost fifty kilometres away.All traffic driving through Mossman will now travel through the lights.