Maintaining our roads

There are over 700kms of roads in the Mackenzie District, 500km of which are unsealed. We spend over $1 million each year maintaining our unsealed roads.

This includes regular grading and the application of new metal every few years to ensure a good surface for traffic to run on and to protect the structural integrity of the road.

Dust

Dust and loose surfaces is a fact of life for gravel roads.  We can do little to combat this, especially during hot summery days. Using oil as a dust suppressant is not permitted on unsealed roads.

There are eco-friendly dust suppressant options that can be applied by approved contractors. If you are interested in this, you can contact Council for more information.

Corrugations

Corrugations are one of the more annoying aspects of unsealed roads.  They are generally caused through bad driving habits such as travelling too fast and heavy breaking and cornering.

The Council’s contractor can grade out some of the corrugations but grading too deep can also affect the substructure of the road allowing water to seep in causing large potholes, soft areas and loose shingle.

Potholes

Potholes are common in the low spot where the road is flat, or there is a hollow or corrugation.  The traffic splashes the fine material that binds the road together and and potholes develop. The Council’s contractor works within the available budget to keep roads shaped with a high camber for water to run off.

Metalling

About 25,000 cubic metres of metal is placed on selected roads each year.  Roads with high traffic volumes can expect to be resurfaced every three years.

Maintenance Grading

By their nature, unsealed roads cannot be kept in a steady state.  Because they are made up of stones mixed with clay or silt fines, just how well they last between grading is very much dependent on the weather and volume of traffic.

Roads which carry heavy traffic such as logging trucks and milk tankers can also suffer increased wear. Most metal roads are graded every month.

Remetalling typically occurs between September and November and again in February to April due to the required weather conditions.  Roads with less traffic are graded less frequently and those with more traffic may require more frequent grading.

The Council can advise when the grader is due. The road surface should remain in good condition for about a week and a half after grading, depending on weather conditions, traffic volumes and driver behaviour.

Monitoring and Inspection

Unsealed roads are inspected regularly by the Council’s Roads Maintenance Contractor who determines whether additional maintenance is required.

Corrugations caused by speeding motorists will generally not result in extra grading whereas corrugations caused by bad weather or heavy traffic may.

Priority is given to the existing maintenance programme and areas the contractor feels require extra attention.  Council staff monitor the contracts and audit the standard of work.

Driving Safety

Three simple rules for driving on unsealed roads

• Accelerate slowly.  Do not spin your wheels, especially through gear changes when entering onto metal roads from a driveway or another road.  Lay off the accelerator where there are already corrugations.  All wheel drive vehicles create micro corrugations through heavy acceleration.
• Slow down.  You will find less dust and less loose shingle.
• Avoid hard braking.  This will reduce potholes and deep intersection corrugations.  Report any intentional damage to the Council or Police.