Highway wire a lifesaver

By SIMON COLLINS

Wire-rope median barriers will sprout on heavily used sections of rural highways if Transit New Zealand's engineering policy manager, Paul Hambleton, has his way.

Mr Hambleton and his Swedish wife, Gunilla, have just returned from her homeland, which has the world's lowest road toll.

He believes New Zealand can halve the annual road toll to Swedish levels, partly by installing median barriers on roads where head-on collisions occur frequently.

"People will look back at this age and wonder why on earth we travel with death so close - only a foot away - and no protection," he said.

Sweden accepts that some motorists will make mistakes, and it designs roads to ensure that the accidents caused by those mistakes do not kill people.

Its Vision Zero policy means, in its own words, "It can never be ethically acceptable that people are killed or seriously injured when moving within the road transport system."

Mr Hambleton said Sweden installed wire-rope median barriers on busy highways in sections where the traffic justified three lanes, with passing lanes alternating at regular intervals from one side of the road to the other.

Initial research on these sections of road recorded zero serious injuries since the barriers were installed.

At first, only 1 per cent of Swedes approved of the barriers, because they trapped cars behind trucks until they reached passing lanes.

But that changed as soon as a journalist recorded the first accident on the restricted highway.

"It was an old woman who was patting her sick dog on the way to the vet and almost had a head-on collision. She banged into the barrier. No one was hurt," Mr Hambleton said.

"Now the public acceptance rate is 80 per cent."

The barriers are at present being installed on the Southern Motorway between Drury and Bombay. Transit traffic design manager Dennis Davis said they would probably be used on other busy highways, but perhaps less than in Sweden because three-laning was less common here.

Mr Davis said traffic levels and crash experience already justified going straight to four lanes on the busiest stretch of highway that is not yet a motorway, the Auckland-Hamilton road.

On the rest of State Highway 1 beyond Hamilton, "I don't know whether you would be able to justify extended lengths of three-laning. It [traffic volume] is just not there yet".

He said Transit would be unlikely to use median barriers on standard highways because of the need for traffic to get past if a breakdown occurred.

Mr Hambleton said Swedish experience confirmed the adage that "speed kills". Reducing speed from 120 km/h to 100 halved the risk of death, and cutting speed to 80 km/h halved it again.

Sweden has imposed a limit of just 30 km/h near schools.

Mr Hambleton said that on the open road the main cause of death was motorists who were simply tired, talking or otherwise distracted.

To keep these people alive when they ran off the road, Sweden had installed wire-rope barriers on the sides of many busy roads, as well as in the middle.

On less busy roads, roadside marker poles had been changed so that they broke on impact, rather than crunching the car and skewering the driver. Other roadside obstacles had been removed.

"If someone hits a power pole, what happens?" Mr Hambleton asked.

"Swedish crash tests show that at 90 km/h, even with the safest car in the world, the pole or tree ends up passing through the back seat of the car with few, if any, survivors.

"In New Zealand we have been encouraging utility companies to put their services underground or away from the highway. We will continue with this strategy."

Feature: Cutting the road toll

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