Also, shape. Go look at the front end of a car like a ford F150. The hood is flat and sits 4 feet high. Now go look at a more compact car like a prius. The hood is low, and is angled like a wedge smooth into the windshield. When a prius hits you, its liable that you will just roll up and off of it and not get much of the force from the impact as a result. When an F150 hits you with its 4 foot tall wall of a grill straight in your chest, I don't think you will be rolling up and over. Maybe your head would just pop off from the kinetic force, sparing you from a slower death?
The overall height, especially of the hood is also really important for the pedestrian's chances. if a sedan hits you, ideally you can roll over the top. if a truck or suv with enough size hits you, you go under it.
The shape of the vehicle has far, far more to do with pedestrians dying than the weight of the vehicle. I would MUCH rather go over the hood of a 4800lbs Tesla model S going 30mph than under the front bumper of a 3900lbs Tacoma.
It makes a big difference where one is hit. Being hit in the head by a head-height truck grille is a lot different from being hit in the shins by a 1964 Datsun. There's also the small matter that nobody driving this truck can see anything at all for ten feet to the front.
Because when a hatchback hits you chances are that you’d get thrown on its hood or windscreen, while when a truck hits you chances are you’d be thrown behind its weels. The first scenario gives you bigger chances of survival as a pedestrian. It’s not a question about mass, it’s about the shape of the car. Of course, this whole scenario applies to speeds generally met in cities/towns (maximum 30-40 kph).
Some passenger cars also have a nifty feature where if an impact is detected, the hood on the side of the windshield is instantly propped up by some springs to provide a cushioning effect to whoever ends up on the hood.
I've seen it action when a guy who I was riding motorcycles with got hit on the side by a car (his fault, low speed, he was fine). My car also has the feature.
Obviously impossible if the hood's too high like with an SUV or pickup.
Agree with this. Another factor is that even if you don't go under, the grill is higher up. If the impact is centered on the legs or pelvis you might have serious damage, but will most likely live. If the impact's near the chest or head, there's a lot of delicate vital organs.
The increase in trucks and SUVs is a major reason why pedestrian fatalities has increased so much over the past decade. (Though the auto industry has tried to shift the blame to cell phones.)
A big factor is the height of the hood. When a smaller car hits a pedestrian, the hood is usually at or slightly under the pedestrian's center of mass, so the person will often roll up onto the hood. In a bigger car the hood is substantially above the center of mass so that a person cannot roll up --- they end up being forced under the car, which is much more dangerous.
It's a lot worse than no car at all - which people understandably don't feel comfortable doing when they're surrounded by vehicles with bumpers as high as their chest.
I get hit by a sedan, I break my legs, it sucks. I get hit by a crossover, I'm thrown forward from my center of mass and likely under the vehicle. I get hit by an F-150, the hood is at head height and I die.
It was hit from the side I think? The height of the pickup definitely made a difference because most of the cabin was sitting up on the median rather than squished into the barrier like the rest of the truck. Your point about the weight is a good one in most circumstances though!
Some poor understanding of physics in many comments. High school physics deals in point masses in vacuums, but people and vehicles are not point masses.
Injury is closely correlated to accelerations applied to various body parts. A sloping hood gives more space to average out the acceleration.
Conversely my stepfather blacked out and fell backwards on a tile floor. A low speed impact with a high acceleration applied to the back of his skull and brain that killed him.
The single biggest design factors on whether a car will kill someone they hit, is its weight and height. And cars are significantly heavier and taller than they need to be.
Getting hit by a Fiat 500 at 35mpg will just have me roll onto the hood, slow my speed, and allow me to either roll over the car or roll off the front again. With most of the initial impact affect my legs and thighs. Getting hit by a Hummer EV will have my head and torso (y'know, the juicy, sensitive bits) getting hit first, with no ability to slow my speed by rolling onto anything, I just get thrown forward into more traffic, or end up underneath the vehicle where my juicy sensitive bits are now able to get run over by a comparative weight of a small elephant.
It would be interesting to compare the effect of vehicle type as well: I'd imagine being hit by an SUV is much more likely to kill than by a smaller car with a lower, softer front.
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