Road construction teams utilize many types of traffic devices to make our commutes safer. Whether it is preventing high-speed accidents that are too often fatal or simply keeping cars and trucks moving safety through rerouted traffic for a large event – safety is always the top priority.
One of the more popular traffic safety solutions is a crash attenuator, also commonly referred to as a “crash cushion” or “impact attenuator”. Crash attenuators can be affixed to trucks, trailers, and road barriers. They are built for a specific purpose – to reduce impact forces through absorbing the colliding vehicle’s forward momentum in the event of a collision. This absorption of energy reduces the forces of impact and the amount of damage incurred, thus saving lives. Crash cushions can be placed temporarily if needed. For example, they could be used for a 24-hour lane closure for repairing a short stretch of road. They can also be permanent fixtures affixed to the end of a concrete median barrier. A truck or trailer-mounted attenuator is used at the beginning of a work zone and protects roadway workers from errant vehicles entering the work zone.
With so many types of attenuators out on the market, you may be confused about which one to pick for your next construction project. Keep reading to learn more about the differences between crash cushions.
Water-Filled Attenuators
When circumstances are right, water-filled impact attenuators can be a great option for hazard protection. They are quick and easy to deploy, more affordable than their steel attenuator counterparts, and available in TL2 (Test Level 2) and TL3 (Test Level 3) configurations. The speed limit of the roadway will be used to determine the correct Test Level. Unlike other crash cushions, they do not require anchoring to the actual roadway. Water-filled attenuators can be used as end treatments for both traditional concrete (aka Jersey) and water-filled barriers.
Truck and Trailer-Mounted Attenuators
Truck and trailer-mounted attenuators are a key component to keeping workers and motorists safe in work zones, saving countless lives every year. These attenuators reduce the risk of workers being struck by a vehicle entering the work zone. They are made from aluminum or steel and are often custom-built.
Steel Impact Attenuators
Steel impact attenuators are used for both permanent and temporary applications. They are required on roadways with higher speed limits and when a non-gating redirective cushion is required. The term “non-gating” notes that a vehicle is not able to pass through the cushion. Steel impact attenuators are more of an up-front investment: however, they are often able to be repaired after impact unlike water-filled attenuators. The cost of repairing a steel impact attenuator is much less than replacing a water-filled crash cushion.
Key Differences and Decision Factors
There are several things that must be taken into consideration when choosing the right attenuator for your specific project. These factors include but are not limited to: how the crash cushion deals with impact, the length of time the device will see deployment, regulatory approvals, setting/roadway (rural versus urban/speed limit), and as with any business decision, budget limitations.
Impact Styles:
Steel impact attenuators are nongating and redirective. Water-filled attenuators are gating and non-redirective.
Timeline:
Truck-mounted attenuators are always temporary and typically used for lane closures to protect workers in the roadway. Steel crash cushions can be permanent but also used in a temporary setting at the end of a portable concrete barrier. Water-filled attenuators can only be used in a temporary setting. It should be noted that permanent crash cushions need to be well-maintained and recertified in the occurrence of an impact.
Cost:
Water-filled attenuators are about one-third the price of steel attenuators. If they are hit in a collision, they are disposed of; in contrast, most steel attenuators can be repaired and have parts replaced over the course of their lifecycle. Truck and trailer-mounted attenuators are required in certain situations; however, the cost will depend on which type is used. We recommend that our customers also consider the likelihood of an impact when deciding on a type of crash cushion.
Regulations:
Some states permit the use of steel attenuators only. In the southeast, Georgia and North Carolina allow water-filled attenuators, while currently, South Carolina does not.
Looking for Crash Cushions? We Can Help!
Understanding all the different varieties of crash attenuators can be hard, but thankfully, our team of experts can help you target the right solution. With offices in the Charlotte and Atlanta regions, we proudly serve companies across the Carolinas, as well as Georgia and Virginia. Contact our sales team, and we will tailor the perfect solution to meet your road construction safety requirements.