In a post in Straight Dope Message Board, run over and run under are used in car accident context, but I can't differentiate them. In my understanding, in both cases the victim is hit directly by the vehicle's front, no wheel runs over the body. I cannot google out an example of run under in the context of car accident (only thrown under the bus, but this is irrelevant).

So what is the difference between run over and run under?

When hit by a car, the vast majority of people are not run over; they are run under. The lower legs break, sending them into the air. They usually strike the hood of the car, often with the back of the head impacting the windshield, "starring" the windshield, possibly leaving a few hairs in the glass. They then go over the top of the car. They are still alive, although with broken legs, and maybe with head pain from the nonfatal windshield impact. They die when they hit the ground. They die from head injury.

A person hit by a bus would actually be run over. There would be two separate sets of injury. The first would be when the kinetic energy of the bus struck the pedestrian. Mass times velocity squared. This is the closest approximation to the ground that your example offers. The likelihood is that they would incur lots of fractures, but not be killed by simple impact. If they were killed, the injury I have seen most often, in my autopsies as a medical examiner, is rib fractures, with the free ends of the ribs bending inward at the moment of impact, to perforate heart and lungs. This is a vanishingly rare injury in fatal falls.

By the way, what is go over the top of the car?

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    I think it's probable that when the phrase 'run over' was first used, people actually would be run over by the wheels of whatever vehicle hit them. However, since cars are shorter now, the effect of being hit by them has changed. Thus, 'run under' is the more correct explanation, while 'run over' is still more commonly used. Feb 14, 2017 at 16:00
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    'Run under' is definitely not a well-known expression. If you don't want to imply that the victim went below the car, you can simply say 'hit by a car' or 'the car hit the victim' Feb 14, 2017 at 17:23
  • I agree that I would never say "run under", but I agree with Jeremy about alternatives to avoid the implication of a victim going under the car. I would probably never say "run over" to mean "hit by a car and tossed over it". Feb 14, 2017 at 18:19
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    Why not simply read the paragraph? It contains the answer to your question. But as Jeremy said, the phrase "run under" is a coinage.
    – TimR
    Feb 14, 2017 at 20:51
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    When cars were first invented (and when vehicles were pulled by horses) they weren't going fast enough to throw you in the air. They would knock you down with the front and the front or rear wheels might then run over you.
    – RedSonja
    Feb 15, 2017 at 15:00

1 Answer 1


"Run under" is not an established expression: this writer has invented it, to make the point that most victims of an accident end up above the car, not under it.

If this idea gets picked up, it may become an established expression; but at present, if you used the phrase without this context, people would probably not understand you.

Edit: Roger Willcocks points out in a comment that the phrase has had some use, so I went looking on the NOW corpus.

  • "[BE] run over" occurs 3311 times
  • "[BE] run under" occurs 528 times. But on looking through the pages, I failed to find a single instance of "run under" in this sense: most of them are something like "the project was run under such-and-such conditions". I'm not saying there are no instances, but there are certainly very few in that corpus. (The one instance I found that I thought at first was pertinent was "I don't feel as if I've been run under a bus," as a simile in an article about the Russian doping scandal. While the speaker might have had this expression in mind, I rather doubt it, thinking that he has conflated "been run over" and "been under a bus".

The NOW corpus, by the way, has 2.5 billion entries, and is taken from Web news, 2010-yesterday.

I stand by my answer above.

Further edit: For comparison, I looked at some of the instances of "[BE] run over". The first twenty "was run over" were all in the road accident sense; but in the first twenty "be run over", only 11 of them were in the road accident sense. So the 3311 figure should be reduced somewhat ("was run over" was the largest group in the output, having 1353 out of the 3311 instances). But we still have conservatively, 2000 instances of "run over" to at most a handful of "run under".

  • Actually, the terminology and a very similar definition have been in use here: sdt.com.au/safedrive-directory-PEDESTRIAN.htm since at least Feb 2011, so I don't think it is either new or unusual. Feb 14, 2017 at 21:48
  • @Roger: That's only 5 years. I'd say that's pretty new. Unusual? Well by the measuring stick of "has the average person heard this before?", then yes, it is.
    – user42899
    Feb 14, 2017 at 23:07
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    If you have access to the full text: jamanetwork.com/journals/jamapediatrics/article-abstract/515188 "Child Pedestrian Injuries in the United States" JAMA - June 1990 specifically references "run under" injuries. That's 25+ years ago. I'd be more inclined to consider it "technical jargon" Since I have an MSc in MedSci, I'm probably not the best judge of "common usage" in this case. Feb 15, 2017 at 1:23
  • @RogerWillcocks I'm not sure what you're arguing here. Fine, you've found some instances with the phrase. That doesn't change the fact that "run under" does not seem to have penetrated the common lexicon. I suspect the vast majority of English speakers (at least in the US) would look at you funny if you said "run under" and would have to explain (which would likely be followed by some eye rolling).
    – Andy
    Feb 15, 2017 at 1:59
  • I've never heard this term used in British English
    – Alnitak
    Feb 15, 2017 at 10:52

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