Rock of cages: Study shows gabions just decorative

Boxed rocks on North John Wayne Parkway [Brian Petersheim Jr.]

Is it time to #FreeTheRocks?

It’s a common phrase we at InMaricopa hear about gabions — the decorative rock cages installed along medians at John Wayne Parkway and Maricopa-Casa Grande Highway last year as part of a city beautification project.

Many believe they serve a functional purpose as well — preventing head-on collisions.

While their low cost and ability to blend with a desert environment has pushed some communities like Maricopa to use them in a decorative capacity, gabions were first designed to act as retaining walls.

But they may not be the premiere safety feature you think they are.

In July, InMaricopa asked readers for their thoughts on these roadside rock cages compared to traditional guardrails.

In the informal poll, more than 4 in 10 Maricopa residents said they believed gabions helped thwart head-on collisions.

“I have seen quite a few cars get stopped by those boxes,” reader Shannon Skoko said. “Seems like they work for me.”

Just 1 in 10 said the structures cause more accidents — but these few voters, like David Leach, might just be correct. Gabions are “too much of a distraction,” Leach said.

An aerial shot of a damaged gabion along John Wayne Parkway. [Brian Petersheim Jr.]
Do gabions have any actual impact during an impact?

Since January 2020, a dozen head-on crashes occurred near the gabions on John Wayne Parkway and Maricopa-Casa Grande Highway.

A public records request showed there were three such crashes in 2020, three in 2021, two last year after the gabions made their debut and four in just the first half of this year.

That includes one in July that resulted in a vehicle flipping onto the median and damaging gabions and other steel art installations.

So, are gabions any good in a crash?

In a 2015 peer-reviewed study, researchers from Queen’s University Belfast decided to put claims of their effectiveness as an economical safety barrier to the test.

Results were less than thrilling.

In a series of crash tests, results showed multiple times that a gabion “is not a suitable safety barrier solution.”

The study concluded that “gabion barriers are already used in some regions as roadside barriers but this study, which resulted in the vehicle rollover in a full-scale crash test, showed that they do not provide good occupant protection.”

So, should we still #FreeTheRocks?