First publishedin World Highways
New barrier concepts offer major gains in highway safety
Highway barriers provide a necessary safety solution for roads and many units are designed to deform during a crash situation, helping reduce the effects of an impact on vehicle occupants. Different standards have been established in the US and in Europe, where much of the development work has been carried out, which has led to a complex situation regarding new products.
In the US, the National Cooperative Highway Research Program
(NCHRP) was established to carry out research in problem areas affecting highway planning, design, construction, operation and maintenance. Devices considered crashworthy are those that have passed uniform crash tests meeting the NCHRP Report 350 guidelines.
In Europe, the CE Marking is the universally accepted symbol of conformity. Beginning in January of 2011, it will become a requirement for crash cushions sold in the European Union to carry the certification. To earn the marking, manufacturers must undergo a certification process which includes comprehensive documentation and testing, along with a facility inspection to examine quality control procedures and monitoring processes. Each manufacturer and its products must meet the standards set out in EN1317-5, ensuring crash cushions are compliant and additional production will continue to meet the same standards and specifications as the product originally tested.
The QuadGuard CEN family of crash cushions from Quixote
subsidiary Energy Absorption
Systems has set a precedent as it is one of only a few crash cushions on the market that is CE certified, as well as being NCHRP 350, TL-3 approved according to the firm. The QuadGuard crash cushions represent the latest technology innovations for shielding hazards, able to absorb the energy of a head-on impact through a controlled telescopic yielding, or redirecting a vehicle when impacted from the side.
Developed for fast installation in workzones, Energy Absorption Systems' Vulcan Barrier is a portable steel longitudinal barrier that meets NCHRP 350 TL-3 & TL-4 and EN-1317 H2 & N2 test requirements as a longitudinal redirecting barrier. Available in effective lengths of 4m and 12m, Vulcan Barrier uses a vertical steel pivot pin to interlink each section allowing the system to follow curves of up to 6º per segment. The lightweight construction and flexibility of the Vulcan Barrier offers an effective solution for many highway maintenance and upgrade projects.
The highly portable Vulcan Barrier can be deployed as a free-standing system and is designed to be used with a variety of end terminal options. Optional castors can be fitted to ease deployment and movement, while the lightweight and stackable design allows up to 160m to be transported on one truck, offering major transport savings. The Vulcan Barrier can also be used in a gate configuration to create easy access through a permanent median barrier or into a work zone.
Noise is another issue that has to be considered in highway construction sites and Italian firm Fracasso
is now offering a new barrier system that combines the dual roles of safety barrier with noise reduction. Well suited to safety applications on urban highways, the system meets relevant European EN1317 standards for restraint and can also cut vehicle and road noise from causing a disturbance to nearby residents.
Fracasso's combined road retaining system features a diffractor device and can be specified to meet an array of restraint requirements, to suit the needs of a particular highway application. At the same time, the acoustic performance of the system can be matched to the specific needs of the installation.
According to Fracasso, its combined system offers another key benefit in that it can reduce installation costs. Because the system offers a combination of restraint and noise reduction capabilities, it provides a lower cost option for clients that would otherwise require separate barrier and noise attenuation products. This combined safety system offers a reduced overall width compared with installations where noise attenuation barriers are located behind the safety barrier. This minimises the amount of land required on a highway installation while the combined structure provides a greater strength than for separate safety and acoustic barrier arrangements. Because the combined system takes up less space, it is also well-suited to the narrow space applications on bridges and viaducts. On sites where the ground is uneven or mountainous, using a combined barrier offers an efficient engineering option, according to Fracasso and a wide array of different variants is now available to suit a range of geographical and technical requirements as a result.
The company has already supplied an array of combined acoustic/safety barrier systems on highways in Italy and intends to boost sales into international markets.