Road gritting and CMA
Dunedin's winter often means our steep streets become slippery and hazardous. We provide a road gritting service as necessary to alleviate the hazard but we encourage all drivers to drive to the conditions. We have also been trialling the use of a chemical de-icing agent, calcium magnesium acetate on selected roads in the city.
When will the roads be gritted?
A report regarding road conditions will be made available each day from the contractor. This report details which roads have been, or are to be gritted. Our contractor will assess the need for gritting when there is a possibility of freezing, and subsequently grit roads as required.
Although there is no specific time that roads are gritted - arterial (major traffic routes) roads will be gritted before 7.30am.
Which roads will be gritted?
Road gritting is done in the following order of priority:
Arterial Routes
Including Kaikorai Valley Rd, Stuart St, or Pine Hill Rd, as well as bus routes. Some very short bus routes linking to major arterial roads may or may not be gritted depending on their condition.
Collector Roads
These are other busy roads such as Ross St that feed traffic to arterial routes. They will be done after arterial roads are completed.
Local roads
These are generally not gritted.
If you are not sure which kind your street is, check the Road Gritting Priority List.
CMA
CMA is a de-icing and anti-icing agent that the city is applying to selected city routes on a trial basis.
CMA is a patented chemical formulation of dolomitic lime and acetic acid. It was first identified as a low corrosion, environmental alternative to road salt by the U. S. Federal Highway Administration in the late 1970s. Today, CMA is used worldwide to answer environmental concerns and solve problems associated with corrosion and concrete spalling.
CMA exhibits very low corrosion rates on metals found in bridges, roadways, parking garages, other steel and concrete systems and is commonly specified by design engineers for use on the previously mentioned structures. Commonly described as being about corrosive as tap water, CMA is often used as the corrosion standard by which other deicers are judged.
- FAQs about CMA from Kissner Salts (opens in a new window)
- Information from Peters Chemical Company (opens in a new window)
CMA trial routes
The following roads are currently on the trial list for the application of the de-icing agent CMA.
| Street name | Description | Three Mile Hill |
494 Taieri Rd - Silverstream Valley Rd |
|---|---|
| Taieri Road |
Kaikorai valley Rd - end 494 Taieri Rd |
| Fea St |
Pine Hill Rd - Orbell St. |
| Orbell St | Fea St - Pinehill Rd |
| Maclaggan St | Broadway - Graham St |
| Brockville Rd | Kaikorai Valley Rd - Dalziel Rd |
| Stuart St (4 Lanes) | Kaikorai Valley Rd - Smith St |
| Stuart St (2 Lanes) | Smith St - Upper Octagon |
| Maori Rd | Arthur St - Serpentine Ave |
| Glen Rd | South Rd - Glen Park Ave |
Who decides whether roads are open or closed?
Roads are only closed as a last resort, after all other options are considered. Only named Transportation Operations and authorised contract staff have authority to close roads. The Police Duty Sergeant can also request closures.
When roads are closed on a weekday, you can contact AA New Zealand (opens in a new window) for road condition reports.
At other times, or for any further information, contact us.
State Highway road gritting
For any inquiries regarding gritting of state highways, please call Transit NZ directly on 0800 44 44 49.
Private gritting requests
We do not do private gritting. If you want to organise gritting on private car parks etc, you can make your own arrangements.
Footpath gritting requests
Sorry, but we do not grit footpaths.
Removal of grit
Grit is removed by our contractor within 3 days of it being spread. If you have concerns about grit not being cleared in your area, please contact us.
Last reviewed: 04 Jul 2008 6:42pm
Phone us on 477 4000
