Sand barrels are used to protect the driving public from the blunt ends of rigid, or fixed, objects such as concrete barrier or bridge abutments. According to the AASHTO Roadside Design Guide, 4th Edition, 2011: “Crash cushions are ideally suited for use at locations where fixed objects cannot be removed, relocated, or made to break away…”
As such, sand barrels are deployed in both work zone and permanent applications to great effect.
The benefits of sand barrels are significant.
How do sand barrels save lives? When a driver hits an array of sand barrels, the tops of the sand barrels shear away as the force of the crash expels the sand. It’s more of an explosion of sand, really, than an expulsion. (See our videos in the shopping cart!)
Sand barrels slow the vehicle down in a short distance, and at a controlled rate. By doing so, the sand in the barrels absorb the energy generated by the vehicle’s momentum, rather than drivers and passengers absorbing the energy and suffering the consequences.
Drivers and passengers can survive hitting an array of sand barrels. Compare that to hitting the blunt end of a concrete barrier at highway speed.
This conversation is of course a very simplified version of the “Conservation of Momentum Principle”, which is discussed in length in the Roadside Design Guide, Chapter 8.4.3.
In the same section, The Roadside Guide also recognizes that a sand barrel array, comprised of individual, unconnected units, is “flexible in shape, depth and width…so that virtually any type or shape of fixed object can be shielded.”