Safety the barrier priority, not cost
Transit New Zealand traffic and safety manager Dennis Davis defends wirerope barriers.
SAFETY has always been, and will continue to be, Transit’s number one priority when choosing what sort of safety barrier to install on New Zealand’s state highways.
Wednesday’s opinion piece by Patrick McGuire, chief executive of the Cement and Concrete Association ( Concrete Barriers Safest Option), implied that initial cost was the preference when choosing the type of barrier. This is unfortunate because it does not reflect the true situation.
Throughout New Zealand we use a variety of safety barriers, both as median and side barriers. We choose the most suitable barrier for the situation.
Barriers protect road users from many hazards. For example, median barriers reduce the risk of head-on crashes by separating opposing traffic while roadside barriers protect road users from coming off the road in hazardous areas.
The point we want to make is that there is no one right answer for every situation.
Different stretches of road call for different solutions. We typically use three types of safety barriers: flexible (wirerope), semi-rigid (steel) and rigid (concrete).
As an example, along Centennial Highway, north of Pukerua Bay, a wire-rope safety barrier was the best solution because it could be accommodated along the middle of this narrow twolane road. It is simply not possible to fit a concrete barrier along this stretch of highway, which has a steep hill and railway line on one side and the sea on the other.
The results of installing this barrier speak for themselves. Since the barrier was installed, our monitoring cameras have captured at least 12 instances of motorists hitting the median barrier and surviving to tell the tale because they were prevented from crossing the centre line into the path of oncoming traffic.
Mr McGuire talks of wirerope barriers preventing traffic from being diverted around an accident scene and causing traffic jams. This is not true. One of the main reasons for using wire-rope barriers is that they can be dropped to allow traffic to drive around an accident.
As for concrete barriers, these are particularly suitable where roads are wide and have generous shoulders. Wellingtonians can observe concrete barriers along State Highway 1 near Porirua and on State Highway 2 between Petone and Ngauranga.
Concrete barriers will also be used in the Dowse to Petone project under way in the Hutt Valley because they are the most appropriate solution for this stretch of road.
We know that motorcyclists are concerned about their safety if they were to hit a wire-rope barrier, which is why we have continued to monitor overseas research. Currently there is no evidence of wire-rope barriers posing any more of a danger to motorcyclists than other barriers.
What is dangerous is speed and, undoubtedly, motorcyclists are more vulnerable.
However, as technology develops, we will continue to monitor trials of products aimed at making barriers more forgiving if hit by a motorcyclist.
We realise that there are several countries where wire-rope barriers are not favoured. But there are many others where they continue to be promoted, for example, Sweden and Australia (Victoria), whose approaches to road safety are held up as a good model for other countries to follow.
All barriers, whether concrete, wire-rope or steel, are designed to prevent crashes by ensuring road users stay on their side of the road. Many factors go into choosing the most suitable barrier and cost is but one factor.
We remain committed to choosing the best options for each situation. New Zealanders can rest assured that their safety is our number one priority.
Dennis Davis is traffic and safety manager for Transit NZ.
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