Throughout Waikato and Bay of Plenty, councils are rolling out their summer road maintenance programmes.
Resurfacing of roads was like a new coat of paint on the roof of a home – it kept the water out and protected the baseof the road, stopping potholes from forming.
For most local roads, this would mean a spray of chip seal, despite people seeming to have a clear preference for asphalt roads.
Here’s a sample of opinions from people in the centre of Hamilton:
NZTA Waikato/Bay of Plenty manager of maintenance and operations Roger Brady also liked asphalt and said it was great for roads that had a lot of trucks and a strong base – but that wasn’t your average suburban street.
“A lot of people think ‘why don’t you just put asphalt on, if it’s better and stronger, it’s going to last longer?’, but the ‘last longer’ bit is actually a function of what’s underneath the asphalt.”
Asphalt is a product mixed together from a number of different-sized stones in a manufacturing plant. It is a dense cohesive product, which needs a lot of energy to heat and special machinery to lay on the road surface.
“The chip seal is a lot simpler and quicker to apply,” Brady said.
“You basically spray some bitumen on the road surface – if you think of the bitumen as waterproof glue – then you spread some stone chip on top of it and then you roll it.”
NZTA Waikato/Bay of Plenty manager of maintenance and operations, Roger Brady. Photo / Andrew Warner
Because of this, asphalt was five times more expensive than chipseal, with higher manufacturing, energy, transportation and labour costs.
For NZTA to co-fund resurfacing of local roads in asphalt, councils must show NZTA that asphalt was worth the investment.
“Fundamentally, local roads are built to a standard where chipseal is the most appropriate surface to put on them,” Brady said.
In Tauranga, city roading contract manager Garry Oakes said the council knew chipseal wasn’t “the flavour of the month” and trialled new surfacing treatments that looked like asphalt, but were cheaper.
“We’re monitoring the life and performance of these new products over time and in different roading environments in the hope that we will be able to use the star performers more widely in the future.”
Mayor Mahé Drysdale said what the transport agency will co-fund is more important than people’s preferences.
“Some people aren’t keen on chip seal, especially if their road has had an asphalt surface since their subdivision was developed, but the alternative of funding 100% of a surface that costs five times as much doesn’t deliver value for money for ratepayers.”
Brady thought developers probably used asphalt in new subdivisions, because they knew people preferred it, but NZTA didn’t make its decisions based on ride quality or customer perception, but on what was the best asset-management decision.
