Council transportation planning manager Don Hill said staff were working on a draft plan change that would see a series of tweaks to city roads, including Riccarton Rd, near Mosgiel.
The draft was expected to be released for public consultation by July, and would include a proposed change in the status of Riccarton Rd to an arterial route, he said.
The council's intention to do so was first signalled in a 2003 study of the area's future transportation needs, and again in a 2006 transportation strategy, Mr Hill said.
"Council has determined Riccarton Rd will become an arterial route," he said.
"We have made that decision."
However, he acknowledged residents' continuing opposition could see the road's future use resting ultimately with the Environment Court.
Residents opposed to the road's use by heavy traffic have already threatened to take the matter to the court.
Mr Hill said a hearing would be held after submissions on the plan change were called for, with any appeal against the hearing panel's decision ultimately leading to court.
In that scenario, a resolution was unlikely until next year.
The developments came even as Riccarton Rd West Safety Society chairman Brian Miller - a Riccarton Rd resident - challenged the council to begin the formal proceedings.
Speaking to the Otago Daily Times last week, he claimed the council had been pursuing a "defacto" status change for the road by treating it as an arterial road when it was not.
He pointed to a new report, prepared on April 20 by council senior traffic engineer Bruce Conaghan, which described Riccarton Rd as "an arterial link" between State Highway 87 and State Highway 1.
That was at odds with the council's own district plan, which contained a road hierarchy describing the same road as a "collector road" - not an arterial route.
"They are determined to make this into an arterial [road], but I wish they would go ahead and do it [formerly]," he said.
Asked about this, Mr Hill said the road was already functioning as an arterial route, creating the need to reclassify it.
"It's just the road's classification is wrong ... the plan change is now coming to finalise that process," he said.
Mr Conaghan's report described Riccarton Rd as an important arterial link for about 2000 commuter and heavy vehicles.
The recent safety audit had identified several changes - including road widening - needed to improve safety for those using the road, while rejecting a series of community suggestions as unnecessary.
The council has $3.24 million budgeted for safety work in 2009-10 and 2010-11, but the money was dependent on a pending application for additional funds to the New Zealand Transport Agency's regional land transport committee.
Last week, the council's infrastructure services committee voted to proceed immediately with minor safety improvements, such as signage and markings, while reconsidering more significant projects in light on the safety audit's findings.
