Lethal Underride Crashes Between Cars and Large Trucks — and what you can do to avoid one

One of the many killers on American roads and highways that never gets enough attention is underride crashes (a.k.a. under-run), when cars collide with and then get crushed underneath the rear or the side of a large truck — typically a semi-tractor-trailer.

This crash happened in Jacksonville, FL, on the afternoon of January 25, 2020, and as can be seen, the car ran right underneath the semi-trailer. (Cropped photo, by kind permission of Mellissa Dzion.)

A major cause of the fatalities in such incidents is the absence of underride-prevention bars, or inadequate ones which collapse rather than stopping the smaller vehicle from getting underneath the truck.

Figures suggest that around 220 people a year are killed in the USA in this type of collision, out of about 4600 deaths a year in total, that involve large trucks. Both are significant numbers.

The underride prevention bar on this truck is that rather unconvincing, rusty beam, low down, across the back end of the trailer. Like far too many trailers, though, this one does not have protective bars along the sides, to prevent smaller vehicles going underneath from that angle. (Copyright image, 2018.)

Cars being swallowed underneath large trucks when vehicles collide represent a stunningly violent and lethal situation.

There are still far too many trucks and trailers out there that do not have good underride protection.

In the above video, there is a direct comparison between a car hitting the back end of semi-trailer from 2013 and one from 2017, with a better underride protection bar. The difference in survivability is massive.

So how do YOU, as a car driver, protect yourself from this terrible danger?

There are three main things you can do:

The first is to always maintain a safe following distance behind all vehicles, but in particular behind large vehicles. If the vehicle ahead of you stops really suddenly (perhaps in a collision of its own) you must have sufficient time and space to stop your own vehicle before you reach the one that has stopped.

Secondly, try never to get sandwiched between two large vehicles — one ahead of you and one behind — unless there really is a lot of space between you and them. If you do get in this situation, look for a safe opportunity, either for you to pass the one ahead of you or to be passed by the one behind. And if you are on a road where that is not likely to be possible, find a safe place to pull off and let them go by.

The above crash-test video from the Insurance Institute for Highway Safety [IIHS] shows two impacts on the sides of trailers, firstly with no underride protection, and then secondly with the AngelWing system.

Thirdly, when driving on multi-lane roads, don’t dilly-dally alongside big trucks. A tire-burst on either vehicle, or any other reason one might swerve, could put your car into that deadly gap between the front and back wheels of the trailer. This is not a situation for panic, just a calm and sensible calculation about how you can move away from the potential danger area.

This can be taken one step further if you are on the road with a lot of big trucks and it is either foggy or icy. Multi-vehicle crashes in such conditions inevitably result in small vehicles being crushed between big ones so that is an occasion where it would be very wise indeed to park in a rest area or leave the road at the next exit.

The best summary regarding the latest standards of underride protection bars, and gaps in the system, is to be found in the above video from the IIHS.


Additional Sources


3 Replies to “Lethal Underride Crashes Between Cars and Large Trucks — and what you can do to avoid one”

  1. Indeed, rear underride guards (although they meet the federal standard) have been proven to be too weak, there is no federal requirement for side guards, and (although other countries have a standard) there is no U.S. federal requirement for Front Underride/Override Protection.

    What can be done about this? Plenty! The STOP Underrides Bill has been introduced in the U.S. Senate and House. Call your U.S. legislators at the Congressional Switchboard: (202) 224-3121 and ask them to cosponsor S.665/HR.1511.

    AND sign & share this petition: https://www.thepetitionsite.com/…/congress-act-now-to…/

    1. Thank you for your comments, Marianne. I apologize for the fact that we/I had accidentally overlooked them until now.

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