Council initiative to smooth roads

Disgruntled Kaipara residents who live off the districts country roads, where negotiating potholes, dust and mud is a daily trial, will be encouraged to hear the council has a plan to smooth out the ruts and bumps.

Kaipara’s rural road network of 1,575 km of which 1,127km are unsealed, are set to receive a makeover in the near future thanks to Kaipara District Council’s (KDC) new roading research project currently under trial.

KDC’s General Manager of Infrastructure, Curt Martin, says the main goals for the project are to improve performance of the unsealed roads by testing different blends of bindings and aggregates to minimise gravel loss, to re-develop KDC’s existing specification for roading materials and lower expenses.

“Our trials currently underway on Beebush and Arapohue Roads, using a new quarry source and a mixed aggregate-lime blend, appear to be performing best to date with signs of reduced gravel loss, increased pavement strength and even a reduction in dust,” he says.

“We need to be creative in our approach in maintaining unsealed roads as our budgets are not increasing and our levels of service are under pressure, we have to do things differently. This is the motivator for us, to develop a different way of looking after our unsealed assets.”

In June 2016 the first trial sections were constructed with six representative sections identified to cover most scenarios; ascending-descending of hills, straight and windy roads, types of soils and modes of traffic.

The sections were designed so each site represents the available combinations of roading materials, with traditional methods alongside the new trail blends containing different rations of lime, enabling comparisons to be made.

The results gathered after the 12 month trials will be used to create a new material specification which will harness the qualities deemed most conducive to reduced aggregate loss, lower roughness and provide greater intervals between grading cycles.

“At the end of the trial period we will hopefully have demonstrated which of the blended aggregates perform better and may identify options for further research,” Martin says.

“We are willing to share our results with our Northland Transportation Alliance (NTA) partners, as the learnings could be applied by our neighbours as well.”

- By Julia Wade

TRIAL: The smooth surface of Arapohue Road in Dargaville is positive encouragement for Kaipara’s rural residents.