Great Dane Trailers | AnnaLeah & Mary

Secretary Duffy,

The Department of Transportation (DOT) engaged Elemance LLC in 2022 to evaluate three current designs of rear impact guards. Unfortunately, Elemance conducted Finite Element analysis of two obsolete rear underride guards that were not current designs at the time of the contract. In fact, both of those designs had been proven a decade earlier to be crash-deficient. The two manufacturers — Great Dane and Wabash — have developed designs with safer, stronger rear-guard designs. Elemance compounded that error by employing an erroneous definition of Passenger Compartment Intrusion. Elemance’s research findings, Heavy-Truck Rear-Impact-Guard Finite Element Simulation and Analysis, are flawed and backwards-looking rather than helpful to the Department and Congress in evaluating current and future rear underride guard performance and regulatory standards.

Please find attached a detailed critique by engineers who are well-acquainted with the underride problem and solutions. This is what the engineers concluded about the NHTSA-contracted research:

In view of the defects in the Elemance report, a follow up study should be commissioned to evaluate examples of current state of the art rear impact guards that have been in service since 2016 and 2017 respectively. The study should utilize the correct definition of PCI and more accurately assess injury risk.

The Department should act promptly to address the flaws in this federal research in order to fulfill its mission to reduce roadway injuries and deaths.

Jerry and Marianne Karth

Note: This critique was submitted as a Public Comment on September 3, 2025, to the U.S. Department of Transportation in response to their Request for Comments on priorities for the 2026 Surface Transportation Reauthorization.

This video created by the Insurance Institute for Highway Safety twelve years ago explains their Rear Impact Guard crash testing research and how the federal standard is failing to protect road users:

This video is a compilation of IIHS Rear Impact Guard crash tests with old and new guard designs for many of the major trailer manufacturers:

This video demonstrates the night & day difference between old and new designs by one manufacturer:

I have seen quite a few underride guard crash tests in the last two years. It’s not something I ever planned to do and it is never easy. Some of them ended in severe underride and it always shakes me up at how quickly life can change forever. In a matter of seconds.

The crash test I viewed at IIHS on January 19, 2017, was particularly hard to watch. It was a test of Great Dane’s newly designed rear underride guard. A Great Dane trailer was what our Crown Vic collided with on May 4, 2013 — with tragic results.

Demonstration of Improvement in Rear Underride Guard; Great Dane Trailers Crash Test at IIHS, January 19, 2017:

They have proven that creative minds can come up with better underride protection. The cars are damaged from the crash, but underride and Passenger Compartment Intrusion (PCI) are prevented. Lives are preserved.

Here is a Youtube video, posted by Cars-Trucks TV, which demonstrates the effectiveness of the improved rear underride guards designed by five of the major trailer manufacturers — Great Dane, Manac, Stoughton, Vanguard, and Wabash — from 2013 to 2017. They received a Toughguard award from IIHS — as announced on March 1, 2017.

Last year, about this time, I posted this: March Historically a Momentous Month for Truck Underride Safety Advocacy; Beware the Ides of March!

Here is an excerpt: It is my fervent hope that, when March 2017 rolls around, we will be celebrating a vastly improved federal standard–enthusiastically and immediately adopted by the trucking industry–for all-around-the-truck underride protection at higher speeds, including now-exempt single unit trucks as well as retrofitted to existing trucks and trailers.

If this seems like a costly venture, try comparing it to the price paid by thousands upon thousands of individuals and families during the past decades of ineffective underride protection–added to the countless precious people who will be saved in the years to come from tragic, preventable death by underride.

We aren’t finished yet, but we have come a long ways!