Customer-LED solution - Surveyor magazine

Highway authorities have probably never been under greater pressure to achieve value for money, and now that imperative is conflated with another - reducing our industry’s carbon footprint in the face of impending climate change.

At Ringway, we believe that innovation can provide at least part of the solution to these twin challenges by pointing the way to a low-carbon future and generating cashable efficiency savings. Our new LED traffic signs are a prime example.

These signs – now being trialled in Scotland (see box) and about to be installed in Lincolnshire – have been designed to deliver, among other benefits, whole-life financial savings and reductions in the carbon footprint of illuminated signage. As both goals are important to our highway authority clients, these signs can be truly said to be customer-LED.

The engineers at our Weston-Super-Mare signs factory set out to exploit the low-power and long-life potential of LED technology as an internal light source for the signs. We also harnessed the know-how of Designs for Lighting, who specialise in highway and urban lighting design. As experts in the use of LEDs for exterior applications, they were able to provide invaluable advice during the technical development work.

“In future, we expect that all signs will be illuminated by LEDs,” says Alistair Scott, managing director of Designs for Lighting. It is not an idle prediction given the significant advantages LEDs offer over other light sources for illuminating signs.

Longevity is the most obvious, and along with that come environmental benefits. Fluorescent lamps have to be replaced every few years, and their mercury – a hazardous waste – needs to be recycled. They are also not so efficient at converting their electric power into luminance.

The low-voltage LEDs used in our signs are powered by 12 volts or alternatively, by solar or wind power, and they have a life expectancy of up to 50,000 hours. That’s 12 to 15 years, all the while using 60% less power than fluorescent tubes.

Of course, such claims would be extravagant if the signs as a whole were not built to last and to perform. We guarantee our LED units for 10 years, and they produce a bright, uniform light.

As LEDs are a small source of light, great care was required in the design to ensure the sign face is illuminated evenly to achieve the uniformity requirements of the British standard (BSEN 12899). All the LED signs’ components, including the rear and front faces, need to be considered to optimise the design. Our LED signs already meet the basic requirements of the standard and we hope to have full HA and BSEN certification shortly.

The LED light source is embedded within a polymer layer sandwiched within the 10mm-thick sign. A dew-resistant film on the sign face cuts maintenance costs to a minimum, while their composite back plate with no scrap value is intended to frustrate would-be thieves.

The potential benefits appeal greatly to our clients who will trial the signs. In Lincolnshire, five ‘keep left’ LED signs are to be installed at a busy roundabout on the A16/A17 at Sutterton as part of a year-long trial. This gets under way as the county council finalises its Highway Carbon Management Strategy & Plan, which goes to committee for approval this month [July].

LED signs are an example of the type of carbon-saving innovation the strategy is intended to promote, according to John Monk, Assistant Director of Consultancy Services. Widespread adoption in Lincolnshire will depend on the results of the trial and a holistic assessment of the signs’ merits, he adds. “The site will give the signs a decent exposure to detritus from passing traffic.”

Such as assessment should take into account their durability and visibility performance as well as the savings from longer maintenance intervals and reduced energy use. Along with any disbenefits, the emissions avoided by substantially fewer call-outs will also need to be factored into that equation, he adds.

“You’re potentially getting financial savings with both elements – maintenance and electricity – but carbon management is becoming a critical issue to all local authorities, with both the national target and local targets for reducing carbon emissions, which are quite stringent,” says Monk. “Street lighting and illuminated signs are one of the most significant sources of emissions for many highway authorities.”

Lincolnshire has around 10,000 illuminated signs. The recent relaxation in the Traffic Signs Regulations allows some of these signs to be replaced with unlit units boasting today’s more reflective faces. The proportion is as yet unknown, he says, but the potential carbon and cost savings from switching the majority that must still be illuminated would still be significant.

“This trial is very much about joint working,” Monk explains. “We work in very close partnership with Ringway, who are our long-term highway maintenance partner.”
Both sides put forward possible improvements to the highways service, and this product “was well worth trialling from a couple of perspectives,” he says – not least, those environmental and maintenance savings.

Considerable though these are, we see further benefits with our LED signs. There are no fluorescent tubes for vandals to smash, and anti-graffiti film is standard to protect the face of the sign. No external light unit means no obstruction in line of sight to high-ride vehicles. And smart foundation fittings make the sign is passive-safe in the event of a collision – all the more so because there is no 240V power source to endanger vehicle occupants, or operatives carrying out repairs.

Safety, after all, is what signing is all about. And through innovations like this, we can deliver sustainable carbon and maintenance savings as we strive to make our roads safer.

Illuminating Scottish trial

In March this year, the first trial of a Ringway LED traffic sign began on a Scottish trunk road.

BEAR Scotland, Ringway’s joint venture with Jacobs and Ennstone, is responsible for managing and maintaining the trunk network in both South-East and North-East Scotland.

BEAR chose the approach to a crossroads junction, heading southbound into Pathhead on the A68, south-east of Edinburgh, for its trial site. The 600mm-diameter warning sign was installed on a standard 76mm pole within a collapsible unit with a NAL RS76 socket – in line with BS EN 12767 Passive Safety Requirements. It forms part of a package of signing improvements designed to tackle accident problems in the area.

The internally lit LED sign was found to perform extremely well in BEAR’s night-time appraisal, says Consultancy Manager Eddie Ross. “The high level of illumination across the whole sign face area provided a uniform and even level of light with no dark areas or shadowing.”

The trial is just one element of the company’s sustainability review. “We are looking at every aspect of the business with respect to sustainability,” Ross explains. “Our client, Transport Scotland, which is an Agency of the Scottish Government, is particularly keen to reduce energy consumption across the trunk network as part of its very strong climate change agenda.

“We’re monitoring the sign at the moment, but in sustainability terms, it speaks for itself. So we’ll be considering the case for using LED signs on a more widespread basis.”

Jonalan Vaughan is the sales manager for Ringway Signs