Reducing the risk on our roads this summer

11 December 2023

Roading is a cyclical industry: there are things that happen year in, year out, to keep our roads maintained. At this time of year, you’ll see the Tararua Alliance preparing roads for resealing, maintaining pavement, fixing potholes, and collecting data for roads
earmarked for renewal next construction season.

While we go about routine maintenance this year, we are mindful of all we’ve learned from responding to emergencies and the need to be ready for any extremes nature might send our way. Going into this summer we are taking extra time to identify the risks to our roading network from the forecast El Niño weather pattern.

The biggest risks to roading crews from the forecast hot, dry and windy conditions are heat stress, fire, fatigue and wind. We recently had a representative from Fire and Emergency NZ talk to the team about working in the heat, the risk of wildfires, and the risks to driving and operating heavy machinery. Keeping our people safe so they can go home to their families every night is our top priority.

At this time of year, it’s easy to get caught out by ‘bleeding’ roads. There are many reasons roads can ‘bleed’ when bitumen melts and rises above the chip. Sometimes it’s the road temperature causing the bitumen to soften, but it can also be high moisture content below the road, how the road was constructed, and traffic impact.

Driving fast on a bleeding road is unsafe, can damage the road and you can also end up with flecks of bitumen on your vehicle. If you come across a road that’s bleeding, please slow down and increase your following distance – these conditions need to be treated with as much caution as driving in the rain. Please call customer services as soon as you can on (06) 374 4080 so we can respond to any areas with melted bitumen. Unfortunately it’s impossible to predict exactly where roads will bleed each summer, and with the size of the network we do rely on the public to report any roads that need attention.

You might wonder why we keep building roads this way when they bleed every summer. There is hearty debate about the use
of chipseal and bitumen in New Zealand, and it’s a national conversation. As a country we have been using bitumen binder and
stone chips to surface our roads since the 1880s and chipseal remains the most cost-effective option for sealing our roads at present. The asphalt highways overseas that can withstand sky-high temperatures would be great but we don’t have the funding base to pay for them at a national or local level.

Road science is constantly evolving and there is an industry-wide shift towards the use of emulsion as a safer and more environmentally friendly seal to phase out hot cutback bitumen, but that transition may take several years and still won’t completely solve the problems we currently face with road seals all over the country. The problems we have now are a result of geology, available and affordable materials and construction, ageing infrastructure and a lot of water. How we build and seal our roads in future is an industry-wide conversation the Alliance is following with interest through Downer NZ.