University research findings will be used to develop speed limits that reflect the real driving risk

Speed limits on some open roads could be lowered because road safety officials believe they are too dangerous to drive at 100km/h.

Transport Agency road safety director Ernst Zollner told the Weekend Herald that officials were working on plans for consistent national speed limits, which recognised that "the optimal speed on a motorway is not the same as on a winding road in the Coromandel". Currently the open road speed limit is 100km/h, which can be reduced to 80km/h or 70km/h for safety reasons on busy sections of city motorways or the edges of small towns.

Mr Zollner said this general speed limit did not allow for dangerous features such as trenches or trees alongside narrow, rural roads, which contributed to the deaths of many drivers and passengers each year.

Transport officials had asked Monash University researchers for their analysis on the right speed for each section of road, based on a combination of road safety, travel times and vehicle running costs.


The results would be used to develop nationally consistent speed limits which reflected the real driving risk. "We have high-risk roads with high speed limits and low-risk roads that possibly could have higher speed limits."

The Automobile Association is keen to see a 110km/h speed limit on straight stretches of motorways, although the Government has previously ruled out the idea.

Mr Zollner said better road design and signs, which gave drivers the right clues to adjust their speed, were also important.

Another big breakthrough would be the introduction of Electronic Stability Control (ESC), which allowed a driver to regain control after over-correcting or skidding. The system will become compulsory for new cars next year, and phased in for used cars after that - SUVs in 2016, large cars by 2018 and all vehicles by 2020.

Overseas ESC is estimated to have cut crashes caused by drivers losing control by up to 30 per cent and by 60 per cent for SUVs, which are less stable because of their higher centre of gravity.

Road safety campaigner Clive Matthew-Wilson said the safety feature was great but New Zealand had been far too slow to introduce it, years after the rest of the world. "It's a complete disgrace. By the time that it becomes compulsory it'll be already present on every vehicle anyway."

Automobile Association motoring affairs manager Mike Noon said New Zealand could not have introduced ESC any earlier because it was not available on enough Japanese used cars, which made up the bulk of the fleet.

Meanwhile research for the Ministry of Transport has found that safer cars and roads have accounted for almost two-thirds of the large fall in road deaths since 1990.


The road toll has fallen to a third of its peak levels of about 750 a year in the late 1980s to 254 last year.

The study by Infometrics chief economist Dr Adolf Stroombergen estimated an extra 12,000 people would have died on the roads if fatalities had continued at late 1980s levels. It concluded that more than 80 per cent of the fall in the road toll could be explained by long-term trends. Of this, 45 per cent was through safer cars and fewer motorcycles, 19 per cent was because of better roads and 36 per cent was because of driver behaviour factors, such as road safety ads and breath testing.

Read also: Why the road toll is falling