The Dunedin City Council has backed the performance of the newly-appointed contractor charged with gritting and de-icing the city's roads.
Downer was awarded the $45million road maintenance contract, but came in for some criticism when contractors failed to grit some roads by the 7.30am deadline on July 1 - the first day of the contract.
However, council acting group transport manager Richard Saunders said the council was happy with the performance of Downer despite the early hiccup.
"Monitoring has confirmed gritting has been occurring as per the contract specifications,'' he said.
Residents again expressed their displeasure with the new arrangement online yesterday following frosts in much of the city and temperatures of -7degC recorded in some areas.
Mr Saunders said much of the disapproval was due to a misunderstanding of the agreed process for gritting and applying de-icing agents.
The council maintained an online map of where grit and de-icing agent, calcium magnesium acetate (CMA), would be applied, but it had not been updated to include the the agreement with Downer.
The council was in the process of rectifying the the issue, he said.
Treatments would be applied only where necessary and even if roads marked on the map had been affected by frost, treatment would not be applied unless needed.
"We have 1700km of roads to look after and on frosty mornings the main focus is on major traffic routes, bus routes and getting people safely off the hill suburbs,'' Mr Saunders said.
"We do not typically grit local roads.
When there is a possibility of freezing, our maintenance contractor routinely patrols set routes, typically the roads with the most traffic, and occasionally local roads for frost and black ice.
"We aim to have major traffic routes gritted by 7.30am but weather isn't an exact science so late frosts or black ice can cause delays.
"Decisions about when and where to apply grit and/or CMA are made on the ground by an experienced maintenance inspector whose objective is to patrol and grit where necessary.''
Contractors could not grit every road and "people will need to expect ice in places and drive with caution during winter'', he said.
If someone was concerned about a road on the usual grit patrol route they should contact the council.
"If the road is outside of our patrol area then it is unlikely the contractor will be able to respond,'' he said.
"It is important people drive to the conditions and if they think it is too risky to drive then we advise waiting for conditions to change or considering other modes of transport.''
Residents had complained online about CMA not being applied where it was meant to be. However, the agent could remain effective against ice formation for several consecutive nights of dry, freezing conditions, he said.
"It works by reducing ice formation and snow bonding to the road by interfering with the ability of particles to adhere to each other and to the road surface,'' Mr Saunders said.
"It can prevent frosts from forming and allow traffic to break up light ice formation.
"CMA is quick and easy to apply, and there are no clean-up costs. CMA is non-corrosive and biodegradable.
"It will make the road appear wet or damp after the first application and then appear dry thereafter. However motorists should always drive with caution, and should not assume there won't be ice on the road after a frost.''
The agent was being used on some roads on a trial basis, he said.
Contractors were also charged with removing grit from the roads within 96 hours and if people had concerns about it not being cleared they should contact the council, he said.
Downer took over the council contract after the previous contractor Fulton Hogan was criticised for failing to properly clean mud-tanks in the lead up to last year's floods.
