Now, I’m only a Cubs fan by marriage. Early on in that marriage, I learned what a die-hard fan is and joined the club. But I’m not as familiar with historical details as my husband. Like, what’s with the 1969 Cubs?
However, I have become acquainted with truck underride history and know that, in 1969, our U.S. Department of Transportation was working on rear underride guard rulemaking — though it never became law until 1996 — and said that they intended to add side underride protection on trucks. Never happened.
After losing AnnaLeah and Mary in 2013 due to rear underride, I was, of course, very interested in the updated rear underride guard rule in July 2022. In fact, I was quite disturbed to learn that NHTSA blew an opportunity to require a level of underride protection proven possible by the Insurance Institute for Highway Safety and nine trailer manufacturers, who were given the TOUGHGUARD award — further evidenced as technically feasible by the survivor of a 2017 rear end truck crash.
Imagine my further consternation when I learned that at least part of the basis for that July 2022 Rear Impact Guard Rule was a NHTSA “engineering judgement concern” for “potential rotation outboard.” What that means is that if the rear guard were stronger at the outer edges of the tractor trailer, that is strong enough to prevent underride, then the car upon collision might rotate or spin out into traffic and collide with another vehicle causing a secondary collision — what the industry dubs “unintended consequences.”
Rear Retrofit Crash Test
Ha! The reality is that a secondary crash such as that would be so much more likely to allow the crashworthiness features (crumple zone, airbags, seat belt tensioners) of the involved vehicles to protect the occupants as intended. Was that really their rationale? Allow people to die under a trailer so that some other fender bender, i.e., non life threatening crash, wouldn’t occur?
I asked an engineer at a university to weigh in on this concern during a February 24, 2023, Friday brown bag lunch TEAM Underride Zoom discussion. Here are the rather garbled notes I jotted down: . . . fear that it would go out into the traffic; misplaced fear; projecting less inertia as it is deflected out from hitting truck — missing the fact that there is no catching equipment on a trailer — energy absorption — the trailer does not catch the car. If it collides at the rear corner, With or without guard it will rotate. The reason rotation takes place. . . because it is the 30% offset. Unintended Consequences.
I asked him to write up his thoughts for me to share and Jared Bryson, Smart Road Operations and Mechanical Systems Innovation Director at Virginia Tech, graciously and creatively obliged.
Baseball & Underride
I’d say that well-thought out explanation should be taken into consideration during a careful review of the July 15, 2022 rear underride guard rule and the questionable (my words) NHTSA decision to decline from requiring life-preserving underride protection at the outer edges of the guard. It’s guaranteed to mean the difference between life & death for more than one person in the days ahead.
Why are we working so hard to get weak rear underride guards replaced?
FARS Coding of a Sample of Rear Underride Crashes
