Vehicles have gotten a lot bigger over the last few decades, particularly when it comes to trucks and SUVs. In particular, hood heights have gotten much taller as trends have shifted towards taller, more aggressive designs. The trend has raised safety concerns around visibility and pedestrian impacts, particularly when it comes to small children. A new research paper has found significant correlations between larger vehicles and pedestrian fatalities.
The study is the work of Justin Tyndall, an Assistant Professor of Economics at the University of Hawaii. Tyndall’s research focuses on cities, transport, and housing. His latest paper, The effect of front-end vehicle height on pedestrian death risk, is published in the upcoming March 2024 edition of Economics of Transportation, and also available on his personal website.
Tyndall’s hypothesis was that vehicles with taller front-end designs could be more dangerous for pedestrians in a crash. In these incidents, the higher front-end is more likely to make contact with a person’s head or torso, inflicting greater injuries. In contrast, a vehicle with a lower hoodline might instead hit a pedestrian’s legs, where injuries are less likely to be fatal. Motivating this research are the sobering statistics on pedestrian deaths from traffic collisions, which hit approximately 7,400 fatalities in 2021, up 77% compared to 2010.
Earlier studies have been done in this area, but many haven’t been able to drill down into specifics like hood height due to the limitations of available data. Tyndall’s point of difference was to source vehicle measurements using the VINs of vehicles that show up in U.S. & Canadian crash data. The paper features a basic analysis of pedestrian deaths per vehicle category, which shows that pickups and SUVs are most likely to cause a pedestrian fatality in the event of a collision. But it’s the statistics on front-end height that prove the most telling.
Armed with this data, Tyndall was able to more precisely analyze the relationship between vehicle size and pedestrian deaths. His analysis determined that front-end height is the best predictor of pedestrian fatalities versus any other vehicle dimension, like weight or wheelbase. For a 3.93-inch (10 cm) increase in front-end height, Tyndall found there was a 22% increase in the probability of a pedestrian death. This analysis controlled for other factors like crash characteristics, to ensure a fair comparison.
The study also determined that women, children, and the elderly were more strongly affected in this regard. Tyndall suspects that this could be in part related to the lower average body height for women, similarly for children and older people.
Split across these categories, the data gets interesting. A 3.93-inch (10 cm) increase in hood height raises the risk of fatality by 19% for male pedestrians. For female pedestrians, it goes up by 31%.
Taking the same 3.93-inch increase in height, for those aged 18-65, the risk increases by 21%. For those over 65, the increase is a higher 31%. The results are the most sobering when it comes to children, however. For those under 18, the probability of death goes up by a whopping 81%. That’s four times higher than in adults, and suggests that shorter individuals may be at much greater risk from vehicles with super-tall bonnet lines.
Tyndall suggests there is scope to improve pedestrian safety by limiting hood heights. If front-end heights were limited to 49.2 inches (125 cm), he estimates there would be 500 fewer pedestrian fatalities every year. He bases this number off the approximate hood height of a Honda CR-V. The SUV is taller than most traditional car body styles, but measurably lower than larger SUVs and trucks on the market.
Of course, Tyndall isn’t the only one looking at this problem. The Insurance Institute of Highway Safety published similar conclusions last year. The agency determined that vehicles with tall front ends were more dangerous to pedestrians. Furthermore, it found that medium-height vehicles with blunter, more vertical front-end designs were also more dangerous. Ultimately, it found that pickups, SUVs and vans with hoods over 40 inches were far more dangerous for pedestrians in the event of a collision. They were 45% more likely to cause a fatality compared to other vehicles with more sloping designs and hood heights of 30 inches and below.
Similarly, a study from the European Transport Safety Council concluded that SUVs and pickups made roads more dangerous for pedestrians, cyclists and car occupants alike. It similarly found hood height to be predictive of greater harm. “A pedestrian or cyclist hit by a car with a bonnet 90 cm [35.4 inches] high runs a 30% greater risk of fatal injury than if hit by a vehicle with a bonnet 10 cm [3.93 inches] lower,” read the study release, a notably similar figure to Tyndall’s own findings.
Anyone can look at a big SUV or pickup truck and guess that it might be more of a threat in the event of a collision with pedestrians. Beyond that, it’s clear that multiple studies have found numbers to back that up. Whether it leads to any change in vehicle design standards remains to be seen, but regulators would certainly have plenty of data on their side if they were to move in that direction.
Image credits: Title – Sven D via Unsplash License, Figures – Justin Tyndall via research paper, Chevy, IIHS
Thank you for covering this important factor that is not being addressed by NHSTA or manufactures. Add reduced front visibility, longer stopping distance of heavier vehicles, and driver height contributing to vehicle speed, and you have some major sources of the dramatic increase in deaths of people outside of cars the last decade.
“If front-end heights were limited to 49.2 inches (125 cm), he estimates there would be 500 fewer pedestrian fatalities every year.” This is where we see if we care more about 500 people/year than the freedom to kill others (mostly with impunity) for aesthetic and marketing reasons. Add in that speed limits and pedestrian crossings are the most ignored laws in this country, and you have the US as a major outlier in the developed world for traffic deaths. (If you want to blow you mind, search “unmarked crosswalks” in your local city or state traffic code!). The crazy thing is Europe has much of this figured out. Paired with better infrastructure, they have pedestrian-oriented crash regulations that all these car companies are complying with. It wouldn’t be much to apply that to the US…except for all the vanity trucks. BTW, I do stuff like read crash reports for a living. There is more where this came from.
All of these studies saying the exact same thing, and absolutely zero actions taken. Wake me when we get some actual legislation.
But since no one ever went broke exploiting human nature (“me want big tough truck so others think I’m big and tough too”), that’ll probably be never.
“Wake me when we get some actual legislation.”
Perhaps you will sleep longer than Rip van Winkle…
Meanwhile, GM decides to raise the hood height of its new Traverse and Equinox.
This is hilarious because it’s all based on statistics which you can use to prove anything and based on a statistician who set out to improve a particular point.
For instance did you know drunk drivers cause 30 % of all accidents? So that means 70% of accidents are caused by sover drivers. Clearly instead of stopping people from driving drunk we should ve requiring they drive drunk and thereby decreasing accidents by 70%. Now that is clearly true using statistics. And it is clearly wrong until you include only 8% of drivers are drunk causing 3p% of those accidents. It is the same scientific tomfoolery used to prove global cooling, oops global warming, oops climate change. As more people drive bigger vehicles more people are going to die from bigger vehicles. So many manufacturers are stopping making cars and more people are buying bigger cars so yes more people are dying from bigger cars. I bet you could make a similar case that government safety regulations are causing more cars to be heavy and with less visibility and thus causing more accidents vy heavy vehicles but the government isn’t going to release those statistics.
Hundreds of years ago most of our current deserts were lush ocean side hearty agriculture communities. Climate changes and now they are deserts. Do camel farts release too much methane and cause beautiful areas to become deserts? No it is mote based on scientific evidence the axis and rotation differences of planet earth. But the meteorologist and weatherman the worst predictors of future events are trusted when they say the sky is falling. It makes a great songbut has no science attached to it.
All 47 pages of his study are there in the link, if you want to show us all where he made an actual mistake rather than make up something unrelated about drunk drivers and then some weird rant about the climate.
I’m sure there are other factors at play here not directly related to height, like visibility and how the deaths have risen sharply while we’ve been waiting for the new GTA game.
He used more pedestrians getting injured now than in the past. He used higher design now than in the past. He ignored more people driving by multitudes now than in the past. It is a gimmick interns use to get published. Noone is publishing interns who write everything is about what you would expect. It has been used to argue climate cooling than climate warming then climate change when proved wrong. But still idiots who read headlines and never bother with facts run around and claim the sky is falling. Of course more people are getting injured by taller vehicles when more people are driving taller vehicles. It’s common sense but no longer does common sense exist. It is true because I think ots true no one looks at the facts.
The findings weren’t “more people are getting injured by taller vehicles when more people are driving taller vehicles” it was a higher likelihood of serious injury from taller vehicles compared to shorter vehicles.
If you don’t understand the difference maybe statistics aren’t for you.
Oh so no proof just likelihood. So just theoretical. Yes that makes it so certain.
It’s a proven likelihood if that’s any help?
Not that it is going to make a difference to you, seeing as your mind is made up that facts don’t matter, but if anyone else reads:
1) The rise in pedestrian deaths also parallels the adoption of smart phones around the same time.
2) The study did control for comparing fatalities only in collisions involving pedestrians. Meaning it is comparing collisions that happened, to collisions that happened. The article also noted that the differences in fatality risk were after “This analysis controlled for other factors like crash characteristics, to ensure a fair comparison” meaning the only significant difference is hood height.
3) Your drunk driving example reads as an obvious conclusion, until you question what percentage of drivers are driving drunk (difficult to measure but can be fairly accurately estimated) and control accordingly to compare the collision rate per mile. To make up an example if 95% of people are sober but only cause 70% of crashes. It makes sense to go after the 5% of drivers having an outsized impact with 30% of crashes. Leading me to:
4) Are there any glaring inconsistencies that you see, in the article as written, or the linked 47 page study that should be noted or explored? Meaning, is there a point to be made here to try to be part of a solution for the problem being discussed?
Or are you just need of more peace in your life?
This guy shows up in the comments here somewhat regularly and almost always has some insane take. I can’t tell if it’s just trolling or if he actually believes what he says.
In this case I believe the facts as I stated them
You don’t have to be correct to believe something.
I prefer “I refuse to accept your reality and prefer to substitute my own.” I mean in today’s society truth doesn’t exist, facts don’t exist, anyone can claim what they want even a almost adult white male claiming he is an adult white female. Heck I look back fondly when white males were given special privileges and just blamed for everything.
Facts exist, you just can’t see them because you’ve spent all of your free time gouging your eyes out. Again, this has nothing to do with the article or the topic at hand. You should try reddit, you’d do great there before you got banned.
Well it’s intuitive and rather obvious that a car with low sloping hood like say a 1970 VW bug or a Ferrari Daytona go under the center of gravity of a pedestrian and the pedestrian would get thrown up and onto the hood or windshield or even over the top of the car. A pedestrian hit by a tall blunt surface is going to absorb all that energy all at once and probably fall under the vehicle. Also more mass = more energy.
Don’t need stats for that.
The stats give you an idea of the severity of the problem and how you should design an empirical study using crash dummies or the like.
And desertification of agricultural areas historically has been tied to salinity deposits due to undrained irrigation, deforestation, and the lack of dust in the upper atmosphere to seed rainfall and other factors not including camel farts. Goats do a pretty good job of deforestation so there is that if you are worried about the ruminant threat.
And if the car is going 25 mph most likely die in either event.
I see you’re back and writing unhinged and baseless rants in the comments section again. Your lack of understanding of basic stuff is always entertaining, it’s unfortunate that you seem to actually believe the nonsense you regurgitate here.
Here come the external airbags. You heard it here first.
The concept has been around for more than twenty years now.
https://expertwitness.trl.co.uk/pedestrian-safety-airbags/#:~:text=Pedestrian%20airbags%20are%20a%20reasonably,models%20of%20Subaru%20in%20Japan.
(flails around and improvises a bit) But the advanced system will insult you in your native language as it saves your life, flame you on X, and crosspost to reddit under the “Why do inattentive pedestrians keep hurting me” while it notes the insertion of and active status of the Airpods you are wearing while you ignore getting hit. Much more advanced.
https://www.youtube.com/watch?v=24GoZHci7b4
Pedophile rings intentionally hit young pedestrians with tall-hooded machines. They then re-animate them with Satanic rituals and keep them in tunnels.
This is all well-documented, people. Do your research!