Highly visible ideas making 
UK roads safer

The House of Commons Transport Committee’s report, ‘Out of the jam: reducing congestion on our roads’ and the new DfT Policy Paper, ‘Signing the Way’ both look to address the issues around congestion and seek to improve the environment on our roads today and in the future. This, combined with recent statistics showing an increase in deaths on British roads of around six per cent, challenges suppliers within the sector to come up with innovative products to meet these needs.

Signs need to be bright at night so that drivers can both see them and read them. Sometimes there is no realistic alternative to direct lighting to ensure this, but in many cases, modern retroreflective sheetings will be an acceptable substitute, where the Traffic Signs Regulations allow. DfT plans to relax lighting requirements for signing, and the increasing practice of turning off street lights to reduce energy costs and environmental impact, also come with the risk of increased danger on the roads.

A clear understanding of how to specify the correct products for different applications is key to reducing the risk of accidents. The best microprismatic sheetings can be much brighter than traditional beaded types, and signs may be adequately bright under headlamp illumination alone. However, especially on lit roads or for direction signs, it is important that high-performance sheeting is specified. 

Water hazard
One of the drawbacks of retroreflective sign faces has been their tendency to black out when dew forms on the surface. This can reduce the retroreflective properties to such an extent that the sign can become illegible to the driver. Dew resistant protective overlay films can make a huge difference to the effectiveness of a sign. These films alleviate the problem by attracting water droplets together to form a membrane across the sign surface allowing normal retroreflectivity to return. At the same time, the water running down the sign has a self-cleaning effect, which also reduces the need for maintenance.

However, the location of many signs is such that retroreflection cannot provide adequate brightness. This might occur where a sign is presented at a large angle to oncoming traffic, for example a No Entry sign, and retroreflection no longer works. Other signs might be mounted high above the road, where little light from headlamps reaches them. In these cases, direct lighting will still be necessary. Concerns about the energy consumption of direct lighting have been addressed by ARTSM members, who can offer a range of low-energy solutions using LED and other technologies. These help meet energy-reduction targets whilst maintaining safety for road users. Advanced lighting systems have reduced energy consumption by two thirds, and also offer greater reliability and low maintenance costs. These systems can also be retro-fitted to existing sign units.

Savings
An example of the saving achieved is the traditional two-lamp sign light consuming 29 watts. The equivalent LED lamp consumes just 10 watts, and saves up to 138kg of CO2 emissions per annum.

Similar reductions can be made with internally-illuminated bollards, where the use of LEDs cuts power consumption and CO2 emissions by half. Multiply these by the hundreds of thousands of lighting units on our roads, and the potential saving is clearly huge – all without compromising the effectiveness of signs or the safety of road users.

Safety of road users is of course a primary concern for all highway authorities. Although vehicles are incomparably safer than they were not so long ago, the consequences of a collision with road-side furniture can be severe, and attention has increasingly turned to the idea of passive safety – accepting that such collisions will inevitably occur, but seeking to minimise their severity.

Passively safe sign posts were used in Scandinavia as far back as the 1980s, as part of a wider concept of designing the whole highway environment to reduce the risk of fatalities.

The first passive sign mast in the UK was installed on the A4 in London in 1996. This mast from Norwegian manufacturer Lattix AS was soon followed by a couple of installations in Cheshire but it was not until the beginning of the new decade that Lattix was used in earnest on the A34 Towcester bypass, a road with a notoriously poor accident record. The installation was a great success in terms of accident reduction and was also hailed for its cost effectiveness as the implementation of the Lattix masts removed the need for expensive crash barriers and therefore reduced the cost to the contractor and the Highways Agency.

Passive safety built-in
Since that initial scheme, passive safety has grown year-on-year not only in sign supports but also in street lighting, which has the second largest number of fatalities after trees (sign posts being the third). Today the need for passive safety will be assessed for all new roads, particularly high-speed, and most will include it for signs and street lighting unless a safety audit determines otherwise. The success of passive sign posts can be measured in ‘successful non-injury accidents’ and SignPost Solutions, the company that first introduced the Lattix mast into the UK have recorded 198 such successful incidents in collisions with the Lattix mast, proving that passive safety really does work.

The passive safety concept has also been extended to the ubiquitous traffic bollard. Various designs are available, from ‘spring-back’ types to deformable products that regain their shape after impact. These not only reduce the risk of injury to vehicle occupants, but also reduce maintenance costs as the self-righting design means that the highway authority doesn’t need to visit the scene to reinstate displaced or damaged bollards. Many designs also offer substantial energy savings by eliminating the need for direct illumination or by substituting solar-powered LEDs for conventional light sources.

A serious safety issue at road works is the need for operatives to cross live carriageways in order to change the signing as work progresses. A development which greatly reduces the need for carriageway crossings is the rotating prism sign. These are remotely operated with a hand-held controller and are ideal for changing lane-closure layouts without exposing the workforce to danger from passing traffic. Carriageway crossings in one Highways Agency area have been reduced by almost 50 per cent.

Seeking more efficient roads
Both the DfT policy paper and the House of Commons Transport Committee report are concerned to provide road users with better information. Smart systems, often referred to as Intelligent Transport Systems (ITS), aim to inform motorists about current road conditions. Drivers with the most accurate information can make the best decisions on routes and travel time to ease congestion wherever possible.

With capital budgets under severe pressure, the cost of implementing such systems on a permanent basis can be prohibitive. However, temporary solutions allow local authorities and contractors to trial a system and understand its effects and benefits prior to making a large investment. Portable variable message signing, queue detection, variable speed limits using existing loop data, journey time managed with Automatic Number Plate Recognition (ANPR), ice detection systems and CCTV integration can all be purchased or hired to provide real time data which can help improve the UK road network for the benefit of everyone.

For more information
www.artsm.org.uk