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All you need to know about SolarLite Active Road Studs for enhanced delineation


Retro reflective studs have long been the favoured and trusted choice for roadside delineation. But in this extended blog, we look at SolarLite Active Road Studs as an alternative and question why today’s modern network is still reliant on an 80-year-old solution.

A Shaw solution to delineation

With a history and reputation spanning more than 80 years, ‘cats eyes’ have become a familiar feature on UK roads as the go-to choice for roadside delineation. Based upon the concept of a headlight beam reflecting in a cat’s eyes, Percy Shaw’s original invention has since become a registered trademark with variants of the product more widely known as retro reflective studs.

Since their introduction in the 1930s, there have only been minor variants to the design of retro reflectors with little change to the method of performance; the reflectors still rely on the beam of a headlight to be seen. This is despite the road network undergoing major changes over the past eight decades including a significant increase in capacity and the introduction of motorways.

With so many more vehicles reliant upon local and strategic road networks, it is important they operate safely and efficiently by incorporating the most effective measures. Whilst retro reflectors have long been the favoured choice, the idea was founded upon the use and design of roads 80 years ago. So perhaps it is time for road operators to consider a more modern solution which is reflective of roads today, such as SolarLite Active Road Studs – hereby referred to as active studs.

A history in the making

Clearview, under its former brand Astucia, developed the first ever solar-powered road studs which were installed in UK roads in 1996. They were the brainchild of Martin Dicks, a London fireman who regularly commuted from his home in Doncaster along the A1 in heavy fog.

Having attended road traffic collisions and with the firefighter mindset of accident prevention, Mr Dicks launched the SolarLite Surface Studs. Unlike traditional retro reflectors which required a headlight to reflect the beam back at the driver, the stud utilised solar power to charge ultra-bright LEDs (Light Emitting Diodes) which proactively emitted light.

As an avid motorcyclist, Mr Dicks then took his invention further by developing a flush alternative which virtually eliminated any above-ground profile that could prove hazardous to riders whilst improving their riding experience with enhanced delineation. The flush studs have since proved to be the more popular option for installation, as the studs sit just 4mm above the surface of the road.

Ten times the benefits

The term ‘active’ refers to the performance of the studs, which use inbuilt sensors to automatically illuminate at dusk and discharge in daylight. This is in comparison to reflectors which are only visible with use of a beam, meaning if the headlights are off or not pointing directly at the studs, such as on approach to a bend or junction, they are effectively invisible.

The LED, which has an output of >100Hz, is visible from up to 900 metres – 10 times further than the 90 metres offered by retro reflectors. Because of this enhanced delineation and increased visibility of the road layout, drivers have 10 times longer to react to changes in the road ahead. To put into context, a driver travelling around 60mph with 90 metres visibility will have 3 seconds to respond whereas a driver travelling at the same speed with 900 metres of visibility will have over 30 seconds to react.

When conducting research, the Transport Research Laboratory concluded that when active road studs are used, drivers are significantly less likely to cross the central white line or move out of a lane on a dual carriageway. It also found braking is more consistent and less erratic and use of the headlight main beam – which risks dazzling oncoming drivers – was reduced.

The direct and indirect benefits born from active studs have been felt by road operators including Highways England, Transport Scotland, tier one operators and local authorities who have expanded their use beyond simply tackling accident hotspots.

For roads with – or perceived to have - hazardous features including bends, dips or junctions, the studs deliver enhanced delineation whilst at complicated intersections, on/ off ramps and lane mergers, they provide improved guidance.

Unlit routes which are hampered by a lack of street lighting or mains power can benefit from a sustainable compromise or if the problem is in an Area of Outstanding Natural Beauty, the studs can provide a non-intrusive solution.

With an operational lifespan of up to 10 years, the reduced maintenance requirements, associated risks to roadworkers and disruption to drivers mean the benefits extend far beyond delineation and road safety. Regardless of the problem, the extended operational lifespan of an active stud compared to a retro reflector will equate to a significant return on investment (ROI) and better value for money.

Proven to save lives

Because of the enhanced delineation and improved driver behaviour, active road studs have been proven to reduce night-time accidents by more than 70 percent at sites including the A4226 in Wales between Barry and Cardiff, known as The Five Mile Lane.

Against a background of an unacceptably high accident record, the Vale of Glamorgan Council chose to install 200 active road studs, providing delineation for the centre line with white studs. On the most hazardous of bends, the carriageway edges were enhanced with red warning studs. Following installation, incidents reduced by 72 percent when compared with the previous three years.

But it is not just areas with a proven accident rate where the studs have proven beneficial. Along the A1 in Scotland, residents, local councillors and transportation groups were seeking improvements to the unlit route due to concerns about general visibility and delineation at junctions and a lack of consistency of signing and road markings.

As the studs are available in a full range of colours (white, red, green, amber and blue) Amey installed 4,100 studs along various sections and nine junctions along a 14 mile stretch of the route from the Scottish border to Granthouse junction. The solution used white and red studs for centre and edge delineation; and amber and green studs to highlight junctions and other egress areas.

Following completion, a survey of local drivers showed 93 percent of respondents felt junction clarity had improved; 95 percent felt the clarity of curved sections of the route had improved, and 78 percent felt more confident driving this section of the A1 during hours of darkness than they did previously.

Putting streetlights under the spotlight

Whilst streetlighting does offer a solution for road visibility, it is not always practical, permitted or affordable. For local authorities managing shrinking budgets and issues such as light pollution, streetlights have been the subject of debate with some councils opting to reduce their use or turn them off altogether. This decision often causes conflict with drivers who require visibility of the road ahead.

The active studs offer an effective compromise to the absence of streetlights as well as a passive solution by removing roadside infrastructure and preserving the local scenery. Whilst studs will not replace the visibility offered by street lighting, they will provide delineation along an unlit road to help guide drivers along their route.

For Highways England, they were faced with the dilemma of addressing a high risk accident location on the M40 due to the topography, road layout and a lack of street lighting in an Area of Outstanding Natural Beauty through the Chiltern Hills.

In total, 7,000 studs were installed along stretches of the road between junctions three and six, which improved visibility whilst preserving the Chiltern Hills escarpment and protecting the area from light pollution.

In Guernsey, drivers had expressed concerns about navigating unlit coastal roads after dark. Most of the roads had limited delineation of the road ahead, with many retro reflectors in a poor condition.

By installing active studs, delineation of the road greatly improved with twice as many drivers feeling safe using the roads after dark compared to before. This achieved the initial objective – improved driver confidence – but also ensured the scenery was preserved as the use of solar power meant roadside infrastructure and access to mains power was not required.

Finding a way through the fog

The A2 and A20 in Kent faced a similar challenge; with an absence of mains power and the routes passing through an Area of Outstanding Natural Beauty and Special Scientific Interest, street lighting was not permitted to reserve the landscape.

However, the road was notorious for multiple vehicle accidents which was often attributed to fog and poor night-time visibility as well as extreme weather conditions including moving mist and fog which resulted in varying day and nighttime visibility.

The high performing LED and the enhanced delineation means that even in extreme weather conditions, including fog, rain and darkness, the active studs are still visible in conditions where retro reflectors would be difficult, if not impossible, to see. Balfour Beatty and Mott Macdonald, who undertook the works, were so impressed with the performance they commissioned further installs along the same route.

Charging ahead with solar power

Just four hours of solar power will fully charge a stud and provide up to 240 hours of visibility. By harnessing free solar energy from the built-in solar panel, the battery is designed to maintain light outputs throughout a full annual cycle to provide effective year-round performance even in countries where daylight is limited, such as Sweden. Here, during three site trials by the Swedish Road Administration, the studs performed consistently and successfully.

As well as unfaltering performance, it was noted the studs suffered only minor damage from snow ploughs due to their flush positioning, whereas retro reflective studs which sat above ground were regularly left damaged beyond repair. To combat this, Clearview constructed a snow plough housing variant to be used in countries where winter conditions require regular snow plough activity. The stud is installed in durable cast iron case, which deflects the snowblade over the stud to protect it.

International success

The active studs have been installed in more than 400 locations including Holland, South Africa and Australia whilst in the UK, the studs are type approved by the Department for Transport and comply with BS EN 1463.

The studs offer a uni or bi-directional function, with uni directional studs typically being used for slip road, multiple lane separation (dual carriageway or motorway) or edge of road delineation. In contrast, bi-directional studs are used in the centre of single lane carriageways to be seen by drivers travelling in either direction.

A decade of performance

Under TD26/04, the Highways Agency has a requirement for all road studs to be checked at least twice a year and replaced if more than 10 percent are not working; if 10 consecutive studs are missing or not working; if any single stud has a loose casing or if a single stud is missing in legal requirement areas such as double white lines.

Whilst an initial drive along the route may be enough to identify such issues, any closer investigation requires roadworkers to put themselves at risk and disrupt motorists with road closers.

Due to their above surface profile, the performance of retro reflectors can begin to diminish after about six months due to dirt building up in front of the reflector or damage caused by vehicles driving over them. This accumulation effectively reduces the studs effectiveness within two years and increases the need to replace them at further cost to the operator, additional risks to roadworkers and disruption to motorists.

Over a 10-year period, this replacement process could be repeated as many as four times during the same lifespan as one active stud. In 2018, Highways England sought long term road improvements to a 10 kilometre stretch of the A38 in Derbyshire, an unlit dual carriageway through the Midlands used by 23,000 motorists daily.

The challenge was bringing an old, degraded route, with small entrance points on slip roads and sharp bends, up to a modern standard with enhanced delineation and minimal disruption. Recognising the long-term benefits of active studs, Highways England decided to upgrade from retro reflective studs and install 5,000 active road studs, along with new white lines and anti-skid surfacing with the intent of not having to carry out major upgrades or road closures for another 10 years.

The proven lifespan of the active stud has been recognised by clients including Buckinghamshire County Council who installed the active studs along the A4128 in High Wycombe and the A413 at Adstock Bends to the south of Buckingham in a successful bid to tackle accident rates. Ten years on, when the road underwent a full resurfacing scheme, the council chose to replace the active studs with like-for-like, having recognised the direct correlation in accident reductions with installation of the studs and the lack of maintenance required over the past decade.

Active solutions for active travel

Although initially established for roadside delineation, the studs’ usage has since been adapted to incorporate active travel for pedestrians and cyclists.

As part of a flagship cycle scheme along Oxford Road in Manchester, studs were installed to highlight the new Dutch-style cycle path to cyclists and make them aware of pedestrian crossings where the cycle path is diverted around bus stops.

The cycle lanes run on either side of the road and behind the bus stops. Diverting cyclists off the road before a bus stop and back onto the road again after, keeps cyclists safe by separating them from the buses as they pull over. However, bus passengers then need to cross the cycle path to get from the bus stop to the pavement.

The client wanted a solution to highlight the area designated for pedestrians crossing the cycle path where cyclists are expected to give way. They also wanted to highlight the path of the cycle lane as it leaves the road and joins it again after the bus stop.

In total, 400 studs were installed with green used to provide delineation on either edge, red used to highlight the crossings, and amber used to mark the transition from and back onto the road either side of the bus stop. Because the studs are flush to the ground, they are safe to pass over for cyclists.

Pedestrians have also benefited from the scheme along two towpaths in Scotland. Following a restoration of the city towpath, Edinburgh City Council wanted to improve safety at the water’s edge after dark. White studs were installed at 10 metre intervals to provide guidance, with red studs being installed at points which could be considered hazardous, such as a narrowing route and green to highlight entry/ exit points.

The project coincided with a similar scheme along Falkirk Towpath in Scotland and in both cases, use of the towpath increased at night. The increase in people therefore created a safer environment for people to use the area alone and subsequently discouraged antisocial behaviour.

Industry recognition

Since Martin Dicks’ invention was first installed in UK roads 23 years ago, active road studs have been recognised by industry experts with accolades including:

  • Highways Awards Road Marking Project of the Year award for the A38
  • Highways Excellence Awards for Enhanced Delineation and Marking Increasing Safety on the A4128 in Buckinghamshire
  • Safety and Innovation Project of the Year at the Institute of Highways Engineers (IHE) Mercia Branch Awards for Chetwynd Road Safety Scheme
  • Prince Michael International Road Safety Award, recognising achievement and innovations which will improve road safety

The studs also contributed to the Excellence in Cycling and Walking award at the National Transport Awards for the Oxford Road cycle scheme in Manchester and have been shortlisted for the 2019 CIHT awards for the Guernsey project.

Counting the cost and benefits

The Department for Transport estimated the financial cost of a fatality on UK’s roads is £2.1 million, not to mention the priceless impact on those directly affected. But effective, preventative measures, such as active road studs, can reduce that figure significantly.

Whilst it is impossible to quantify the personal loss, we can help in understanding the financial savings active studs can bring. Our Return On Investment (ROI) calculator will enable you to input a road type, inflation cost and accident cost against the Killed and Seriously Injured (KSI) reduction goals.

Whilst the initial cost of an active stud may be higher than retro reflectors, the long-term costs are significantly cheaper which offer operators greater value for money. One stud, with an operational lifespan of up to 10 years equates to one set of road closures per decade with one set of disruption to motorists and risks to roadworkers.

Compare that with retro reflectors. Over the same period, up to four studs may be needed, with four sets of road closures, four sets of disruption and four times as many risks to roadworkers. That is without taking into consideration the salaries of roadworkers and use of machinery.

Then consider the benefits; enhanced delineation, increased reaction time, greater driver confidence.

Active road studs do more than deliver a proven, award winning road safety solution. They change driver behavior. They reduce the frequency and costs of maintenance. They minimse disruption to drivers and reduce the risk to roadworkers.

With so many advantages and benefits, is it not time for road operators to reflect on active road studs and consider them to be the natural choice for effective and enhanced delineation?

Author: Jemma C |Date Published: June 2019

Links: Road Safety

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