Paint test proves a trial
While motorists continue to play their part on a daily basis, mystery surrounds the longstanding ‘‘Paint Trial’’ on Fergusson Dr at Silverstream.
The 150-metre stretch of horizontal lines across a southbound lane has been in place for eight years and, in much reduced form, is continuing to help identify the best paints to use on New Zealand’s highways.
When the NZ Transport Agency first approached the Upper Hutt City Council to use their favoured location the trial was meant to be for three years.
The longevity is, in part, a result of the trial hitting a bureaucratic speed bump midway through the original 2010-2013 work when the road was dug up and resurfaced by the council.
‘‘That was interesting and I can imagine there were a few tough conversations around that at the time,’’ NZTA lead adviserpavement John Donbavand said on site at Silverstream.
That trial was consigned to history and started afresh in March 2013, the same time a similar project on State Highway 1, half a kilometre south of Te Horo got under way.
They are the only paint trials in place in the country, Donbavand said.
Many of the paints tested at Silverstream were also under scrutiny at Te Horo and its alternative chip seal surface.
Sixty-eight products from five paint manufacturers were used at Silverstream.
Four lines were laid for each, two directly onto the ‘‘asphaltic concrete’’ and two laid down over markings put in several months earlier in preparation.
With Opus Research carrying out the technical work the lines were inspected after they had been crossed by 500,000 vehicles, then 1 million and then, in October 2014 at 1.5m when the bulk of the analysis was completed.
Each line’s skid resistance, visibility (in the day and with headlights), wear and colour fading was inspected to reveal just how safe, visible and durable each products was.
‘‘Some were trialled longer, to the five million count which we hit in September last year
‘‘The materials we use to mark the road are just as important as the markings themselves,’’ NZTA regional transport systems manager Mark Owen said when the Silverstream and Te Horo projects were launched.
‘‘They have to be bright enough to see in the daytime, reflect enough light at night to be easily seen and stay visible in wet conditions when we most need them. On top of all that, they also have to be pretty tough.’’
The Silverstream location offered several advantages, Donbavand said.
‘‘It is a straight stretch which is important and we needed an area where the speed was more than 70kmh.
Donbavand said the paint trail was ‘‘quite expensive’’ to set up and maintain but because the costs were met by the paint manufacturers it was cost neutral for the NZTA.