Highway Road and Bridge Safety Barrier System
Road safety barrier systems are engineered barriers designed to protect drivers and pedestrians from being injured in the event of an accident. These systems are installed along roadsides and outline a barrier that ensures drivers stay on the correct side of the road. They also help define lanes, create traffic calming areas and reduce the risk of head-on collisions. The barrier system is available in a number of different materials and sizes and can be used in both urban and rural settings. The finish available is usually cement or polyurethane, and a range of colours are available to suit any project. We manufacture and supply highway road safety barrier meeting New Zealand Standard and international quality requirements set by other countries.
Our road safety barrier system comprises generally following one or a combination of the following components:
•Roadside and Median Barriers,
•Bridge Barriers,
•Crash Cushions and End Terminals,
•Barrier Transitions.
SELECTION OF ROAD SAFETY BARRIER SYSTEMS
Minimum Performance Standard
The minimum performance level for a state highway road safety barrier system is NCHRP 350 Test Level 3 (TL-3). However, in many circumstances, barriers complying with higher test levels will be necessary because factors such as traffic conditions, traffic volume and composition and the cost effectiveness of various safety alternatives must all be considered in the design of road safety barrier systems.
Designers should determine the performance level required for a roadside/median barrier on a case by case basis after due consideration of all factors involved. For example:
(a) The standard roadside protection is a TL-3 barrier but some features, such as a school playground located close to the toe of fill embankment on the outside of a high speed horizontal curve, warrant the provision of a higher performance roadside barrier.
(b) High proportions of heavy and/or dangerous goods vehicles in the traffic stream will usually require TL-4 barriers as a minimum.
(c) Even higher performance barriers, ie. a TL-5 barrier that will contain 36,000 kg truck or a TL-6 barrier that will contain a 36,000 kg tanker, should be used at locations where there are high proportions of heavy
and/or dangerous goods vehicles in the traffic stream, and there would be serious consequences if such a vehicle penetrated, or rolled over, the barrier.
(d) The standard bridge edge protection is a TL-3 barrier but the Transit New Zealand Bridge Manual (Bridge Manual) edge protection criteria will often require the provision of a TL 4 barrier, which will contain an 8,000 kg truck, in most cases.
The Bridge Manual contains a method for determining the appropriate barrier test level for any given situation and it must be complied with when dealing with barriers on bridges. The method is also equally relevant for determining the appropriate test level for roadside and median barriers.
APPROVED ROAD SAFETY BARRIER SYSTEMS
only those road safety barrier systems listed in NZTA M23: Appendix A are approved for use on state highway roads.
Other products that have met NCHRP 350 requirements, may be approved for use on state highways, on application to the New Zealand Transport Agency Traffic and Safety Manager.
Road safety barrier systems used on bridges must conform to the requirements of Transit New Zealand’s Bridge Manual.
The approval of NZTA Traffic and Safety Manager is required for a road safety barrier system to be listed in NZTA M23 Appendix A.The primary criterion for the approval of a barrier system is that it must have been successfully crash tested and the results evaluated in accordance with the National Cooperative Highway Research Program Report 350:Recommended Procedures for the Safety Performance of Highway
Features(NCHRP Report 350).In addition, consideration will also be given to the following:
•In-service Performance: In the case of a product with no demonstrable in service history an in-service trial is required, at the manufacturer/supplier’s cost or otherwise agreed with NZTA.
•Availability of SparesThe manufacturer/supplier will need tofor Maintenance:demonstrate that spare parts are available within an agreed timeframe.
If a road safety barrier system has not been crash tested in accordance with NCHRP Report 350, and its use on state highways is likely to be cost effective, then an alternative crash test regime will be considered, providing:
•the testing has been undertaken by a reputable crash test organisation, and
•the results certified as complying with an equivalent NCHRP Report 350 test level.
