What Makes a Crash Cushion “Smart”
Whether you call them highway attenuators, crash cushions, or impact attenuators, their essential job function remains consistent. Crash cushions are roadway devices designed to protect structures, vehicles, motorists, and roadway workers by absorbing the kinetic energy from a colliding vehicle. Typically placed in front of fixed structures along the highway, such as overpass supports, jersey barrier end points, and gore points, crash cushions are a frequent sight while driving. With multiple styles to choose from, learn what makes them unique and what makes a Smart Cushion® a “smart” crash attenuator.
What are some attenuator differences?
Gating versus Non-Gating: When you hear an attenuator is “gating” or “non-gating,” it means an attenuator that is designed to allow a colliding vehicle to enter the clear zone where it can decelerate safely before coming into contact with any hazards. Non-gating attenuators fold away (or gate) when impacted from the side to allow vehicles to safely pass and are ideal when the clear zone is large enough to safely accommodate a colliding vehicle (at least 75 feet x 20 feet). Non-gating attenuators require a smaller clear zone as they do not fold but work towards slowing the colliding vehicle and are typically seen in medians and shoulders of the road.
Re-directive versus Non-Redirective: Like a gating attenuator, a re-directive attenuator requires more space. It deflects colliding vehicles back into the clear zone and away from danger. A non-redirective attenuator does not deflect and works to slow the colliding vehicle in place.
What is so smart about a Smart Cushion® attenuator?
After learning about gating and redirective options, what is so smart about a Smart Cushion® – a non-gating, re-directive impact attenuator?
Speed dependent energy management: it is speed-dependent, meaning it varies stopping resistance during an impact. It allows lighter and slower-moving vehicles to have longer ridedown distances and lower ridedown g-forces by using a hydraulic system to ensure that the proper resistance is used to stop the vehicle before it reaches the end of the cushion’s usable length. With no expendable parts for design impacts, dozen of impacts can occur without requiring new parts beyond two shear bolts.
Skid frame: the skid frame design was specifically created to allow easier transportation to the job site, as well as smoother attenuator handling, placement, and anchoring to its final location.
Robust side panels: The durable side panels reduce the need for the majority of side impact repairs. Minimal damage means a quick 30-minute resetting process to reduce worker exposure to traffic, as well as lower costs for traffic control, replacement parts, and labor. It also has an extremely low angle of exit on side impacts to keep vehicles from rebounding back into traffic and causing secondary accidents.
Roller guide and rail attachment: the roller guide and rail attachment design on the front sled produces a smooth, aligned collapse by reducing friction and binding when impacted.
Taper design: The Smart Cushion® features a reverse-tapered design to eliminate side panel stress during a collapse. This provides an efficient collapse of the system without significant panel damage, which is why head-on impacts rarely require significant repairs.
There are many choices when it comes to crash cushions. Whether you have a large or small clear zone, weighing the various options before selecting an attenuator is critical. If you’re in the market for a non-gating, re-directive attenuator, the Smart Cushion® impact attenuator is designed for maximum safety and reusability, as well as outstanding durability before, during, and after an impact.