The agreement appears to leave a Dunedin City Council decision to select Riccarton Rd as an arterial route in limbo.
Riccarton Rd West Safety Society chairman Brian Miller said his group had agreed with Meridian that if he dropped his Environment Court appeal against the wind farm, the company would make sure only three oversize vehicles a day, and no more than seven a day, would use Riccarton Rd.
Under the agreement, no other construction traffic would use the road.
Residents have been concerned about the effects on their road of increased vehicle movements and the possibility of trucks weighing up to 125 tonnes and as long as 60m using it, if the company's Project Hayes wind farm is built.
The council has identified Riccarton Rd as an arterial route for heavy traffic, and has plans to widen the road between Dukes Rd and State Highway 87, and strengthen pavement and build a bridle path on Riccarton and Dukes Rds.
The cost was recently estimated at $6.9 million.
Now it appears Wenita Forest Products may be the only major user of the road for transporting logs from the 10-year harvest of its forest north of Mosgiel.
Mr Miller said Meridian had also agreed to carry out a vibration analysis on the road at its expense, as well as a road safety audit.
He had agreed not to launch any more appeals against Project Hayes.
Riccarton Rd action group secretary Glen Munn said her group had an assurance in writing from TrustPower that it would not put traffic on the road, in return for the group's submissions being dropped.
Dunedin city councillor Andrew Noone said when contacted policing such an agreement would be difficult.
He said it would be hard to tell the difference between a truck travelling to the Project Hayes site and one travelling to a Taieri farm.
Cr Noone also believed the agreement would have to be ratified in some way.
"I would imagine it would have to be a condition of consent," he said.
But if the agreement did go ahead, Cr Noone said any Environment Court decision would effectively override the council's aspirations for the area.
Mr Miller responded the agreement was outside the Environment Court process, and did not have to be ratified, and Ms Munn agreed.
Meridian Energy and TrustPower did not return calls late yesterday, so the companies' preferred route through the Taieri was unknown last night.
