The council on Saturday published a notice of requirement for the planned $5.4 million upgrade of Riccarton Rd West, a 4.2km stretch from Gladstone Rd South to State Highway 87.
The notice would allow the council to build the roading improvements on land that was at present privately owned and not zoned for the purpose.
It would also allow the council to take the land it needed for the project, under the Public Works Act, if residents refused to sell, council transportation planning manager Don Hill confirmed.
Mr Hill insisted the council was "not proposing to do that at this stage", and was instead planning to make the first approaches to landowners about purchasing land in the next week.
However, Riccarton Rd residents spoken to by the Otago Daily Times said the majority of those living in the street opposed the planned upgrade, and would be reluctant to sell parts of their properties.
Riccarton Rd West Safety Society chairman Brian Miller - a resident for about 25 years - criticised the council's move as undemocratic.
He said the council wanted 2m of his property's frontage, but the loss of the land would be "catastrophic" for his greenhouse vegetable and herb-growing operation.
He believed the council should abandon the project and divert heavy traffic down more suitable streets in the Mosgiel and Taieri area, or buy his entire property.
He vowed to fight against the loss of his land at a public hearing for the notice of requirement - expected to be held in January - and, eventually, the Environment Court.
"I have been waiting for this opportunity for a number of years."
Riccarton Rd Action Group secretary Glen Munn said she was "sick to the back teeth" with the ongoing uncertainty about the road's future, after more than a decade of debate involving the council, but vowed to continue the fight.
"They [council] have put the residents of Riccarton Rd through hell for the last 10 years. I suppose this is the culmination of it," she said.
"It will go to the Environment Court, I'm absolutely certain."
The plan for the road was for road widening, other safety improvements and a shared path for pedestrians, cyclists and horse riders.
The council cited the need to improve safety on the route as the driving force for the project, debate over which has dragged on for up to 15 years.
A safety audit, commissioned by the council, in April found the road's narrow width - between 5.5m and 6.5m - and lack of road shoulders was threatening the safety of cyclists and pedestrians.
In February, a 36-year-old refuse collector was killed after being struck by a passing van while working.
The death was the second fatality on the road in 16 months.
However, opponents argued the safety argument was a "red herring" used by the council to justify turning the collector road into an arterial route, and argued safety could also be improved by removing heavy traffic.
Work to upgrade the road was expected to be completed in stages over 18 months, and was not due to begin until 2012 or 2013, the council's notice said.
Mr Hill said the council would begin approaching landowners about possible sale agreements in the next week or two.
Without opposition from residents, land acquisition for the project could be completed as early as May next year, Mr Hill said.
However, the likely opposition would add 18 months to the process.
A report by Mr Hill, to be considered at today's council infrastructure services committee, said many landowners supported the project, but acknowledged it remained a "contentious issue" likely to be resolved in the Environment Court.
