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Clearer lines, safer roads with ARRB’s iLINE

An ARRB iLINE vehicle
David Milling, ARRB National Portfolio Leader for Safer Asset Performance.
David Milling, ARRB National Portfolio Leader for Safer Asset Performance.

The Australian Road Research Board is using its cutting-edge iLINE technology to provide data on the condition of road line markings.

Clear line markings are critically important to the safety of Australian roads, but measuring and maintaining their performance can be a time-consuming process.

Not only is the optimal day and night performance of line marking critical for drivers, but increasingly so for vehicles equipped with lane guidance technology – something that will only become more important for the inevitable driverless vehicle revolution.

David Milling, Australian Road Research Board (ARRB) National Portfolio Leader for Safer Asset Performance, says the importance of clear line markings and their timely upkeep is often underestimated.

“Line marking is the one consistent attribute of a road that is stipulated by a national standard,” he says.

“But there are intricacies involved in providing and maintaining high performance line marking that not everyone understands, such as different paint types, different paint thicknesses, reflective glass bead size and quality, and how these all contribute to one product outlasting another.”

Variations in line marking and road surface type, lane width and the number and size of vehicles result in highly variable line marking performance across the Australian road network. Monitoring this performance over time is complex and time-consuming, which has lead to the wide data collection approach that ARRB champions.

“We started looking at line marking reflectivity performance with the Queensland Department of Transport and Main Roads back in 2014, when they identified an issue with line marking not reflecting during wet weather,” Milling says. “We started doing some trials with some innovative products, and procured a vehicle-mounted retro reflectometer as part of that.”

An ARRB iLINE vehicle
The iLINE can measure both left and right lanes at the same time, as well as central pavement markings and RRPMs.

Traditionally, line marking performance was measured with a handheld device at a few sample locations. This was costly, required lane closures, placed traffic controllers and staff on the road, and the resulting data set was limited.

Milling says in some cases, due to the inconvenience of collecting with the handheld device, line marking condition was recorded based on visual observation, which is highly inaccurate.

“Usually, you’d need to get traffic control involved, close the lane, and use a hand-held meter to take readings,” he says. “And you might only pick up 12 points along a five-kilometre section. With vehicle-mounted technology, you can get one reading every metre.”

This increase in available data opened up a world of possibilities for ARRB, but the technology was not without its limitations.

ARRB’s original vehicle-mounted unit was bolted to the side, restricting its ability to read edge lines if they were too close to a curb or safety barrier.

“It was also difficult to collect the centreline on a rural highway, because you’d have this unit hanging over the side with vehicles coming the other way,” Milling says.

This is where ARRB’s new iLINE comes in. The front-mounted device means no equipment protrudes from the side of the vehicle, one of several major safety benefits.

The iLINE is also capable of measuring both left and right lanes at the same time, as well as central pavement markings and raised reflective pavement markers (RRPM).

“The ability to pick up data on the left and right-hand sides at the same time means we don’t have to do two passes, and it also means that we have a stronger data set,” Milling says. “Depending on the type of road, you will find that the left or right line deteriorates quicker than the other. So, we can measure and record the retro-reflectivity of that stretch based on whichever side is underperforming.”

Milling says the iLINE can operate at speeds up to 120 kilometres per hour, day or night – a huge benefit when mapping line marking condition on regional highways.

“Previously, if you were setting up a traffic control site to take readings with a handheld reflectometer, you’d be able to set up 500 metres,” he says. “Now we can measure those 500 metres in about 20 seconds.”

ARRB has already put its iLINE fleet to the test and is still exploring the data’s potential uses for councils and road authorities. When combined with ARRB survey vehicles that collect other condition data such as the roughness, rutting, cracking and texture of roads, the end result is a comprehensive data set that can be used to build a detailed network performance plan.

iLINE data
The iLINE can record line marking data points every metre, at speed.

“We have used our iLINE vehicles to map the Queensland network, which is about 26,000 kilometres of sealed roads,” Milling says. “Based on that, we’ve developed an evidence-based remarking program, which allows them to identify which sections of which roads require line marking.”

Milling says road authorities will usually operate on a fixed cycle to schedule which roads are remarked and how often. Then, prioritised roads are often remarked along their entire length. With the data provided by the iLINE, plans can be more targeted, based on the needs of specific sections.

“If they have the data at that high frequency, it allows them to say, ‘well, we might get another 12 months out of this one’, or ‘we might only need to remark 50 per cent of that one’,” he says. “The iLINE allows that much higher level of detail.”

This means funds can be allocated accordingly, and line marking budgets can be stretched further – on top of savings from reduced use of road closures and traffic management.

Milling says there are often sections of a network that may require a different type of paint – whether due to the frequency or type of traffic they are subjected to.

Of course, the tougher the paint, the more costly it is. But ARRB’s data set allows that paint to be deployed only where it’s needed.

“There could be a section of road that connects an industrial area to a port, and the line marking might deteriorate quickly in that section,” Milling says. “We can collect evidence of that in the data, and the road authority can put a more durable and longer-lasting paint down. That way, they don’t have to remark it every 12 months.”

Milling says line marking performance data can also be used in combination with road safety and weather data to prioritise remarking based on crash risk.

“If our data identifies that a road has a higher crash risk in wet conditions, the road authority can use that to evaluate the need for a special wet weather performance line marking product.

“That’s what the iLINE is all about. It’s just one example of how ARRB uses state-of-the-art technology to help improve Australia’s road network. By gathering more data, we can help councils and road authorities make more informed decisions; and develop evidence-based, cost-effective programs to improve road safety.”

For more information, visit www.arrb.com.au/iLINE or contact info@arrb.com.au

This article was originally published in the September edition of our magazine. To read the magazine, click here.

 


 

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