3 ms·

A human isn't going to have much effect on the mass of a smart car, but something like a planter, another car, a curb, a tree, the front of a 7-elevn etc. is go

A human isn't going to have much effect on the mass of a smart car, but something like a planter, another car, a curb, a tree, the front of a 7-elevn etc. is going to stand a much better chance of stopping a smart car than it is a 4,900 + lb. F-150 that carries its weight up high. If there is a tree between me and a speeding car, I would much rather it be a Smart car than just about any other car.

rootusrootus 3y ago
I don't think I'd feel too safe no matter what. There are good odds that the smaller car is moving faster than the big clumsy pickup, and so the car is likely to have at least as much, and maybe more kinetic energy. Also, bumpers on pickups are actually pretty low. Any normal bollard or concrete planter is going to be pretty effective. No pickup is going to drive over something like that.
- dghlsakjg 3y ago
  Why are there good odds that a smaller car is traveling faster? Pickup trucks and SUVs don’t noticeably lag behind traffic or travel slowly in my experience. The scenario I was discussing is when there isn’t a bollard but some other barrier specifically designed to stop a vehicle. A higher center of gravity and larger wheels will certainly help get over many obstacles that would otherwise stop a smart car. If you had to bet which car was more likely to be deflected by a curb strike and which would not, I have a hard time believing you would put your money on a truck vs a small car.
Aurornis 3y ago
> but something like a planter, another car, a curb, a tree, the front of a 7-elevn etc. is going to stand a much better chance of stopping a smart car than it is a 4,900 + lb. F-150 that carries its weight up high. This is another area where looks can be deceiving. Those large vehicles also have large frontal areas and large crumple zones to absorb impacts. Those small smart cars have small frontal areas and relatively rigid frames because they can’t crumple on impact. It’s not hard to imagine scenarios where a small, narrow smart car would literally slip between obstacles where a larger vehicle would get hung up on them. This is especially true for typical bollard spacing. > If there is a tree between me and a speeding car, I would much rather it be a Smart car than just about any other car. I think you’re overestimating the difference it would make. Like I said above, the smaller area of a smart car makes it less likely to actually catch the tree (by definition) and the relatively rigid frame isn’t doing much to dissipate the energy it’s carrying. Looks can be deceiving. I know everyone wants to believe smart cars are super safe alternatives, but any of these thousand pound vehicles isn’t going to be good to go up against. The differences are more nuanced than your eyes would tell you.
- dghlsakjg 3y ago
  Do you have any sources or reading about this? I would love to see something more than conjecture about a VERY unintuitive idea. Newton was pretty adamant that an object weighing 5k lbs (an F-150) would impart quite a bit more force than an object weighing 2k pounds (an economy car). If all of the force is being imparted into a planter, a tree, or the front of a 7-eleven, I'm still inclined to believe that more force, higher off the ground, is going to matter a whole lot more than a few extra square feet. One way or another the energy is going somewhere, and there is A LOT more energy in a pickup truck. Also, keep in mind, the crumple zone protects the passenger compartment, not the object being hit. The bumper of an f150 is right in front of a ladder frame to which several thousand pounds of iron machinery is bolted. I'll still take the smaller, faster stopping, more maneuverable, less energetic battering ram.

rootusrootus 3y ago

I don't think I'd feel too safe no matter what. There are good odds that the smaller car is moving faster than the big clumsy pickup, and so the car is likely to have at least as much, and maybe more kinetic energy. Also, bumpers on pickups are actually pretty low. Any normal bollard or concrete planter is going to be pretty effective. No pickup is going to drive over something like that.

dghlsakjg 3y ago
Why are there good odds that a smaller car is traveling faster? Pickup trucks and SUVs don’t noticeably lag behind traffic or travel slowly in my experience. The scenario I was discussing is when there isn’t a bollard but some other barrier specifically designed to stop a vehicle. A higher center of gravity and larger wheels will certainly help get over many obstacles that would otherwise stop a smart car. If you had to bet which car was more likely to be deflected by a curb strike and which would not, I have a hard time believing you would put your money on a truck vs a small car.

Aurornis 3y ago

> but something like a planter, another car, a curb, a tree, the front of a 7-elevn etc. is going to stand a much better chance of stopping a smart car than it is a 4,900 + lb. F-150 that carries its weight up high. This is another area where looks can be deceiving. Those large vehicles also have large frontal areas and large crumple zones to absorb impacts. Those small smart cars have small frontal areas and relatively rigid frames because they can’t crumple on impact. It’s not hard to imagine scenarios where a small, narrow smart car would literally slip between obstacles where a larger vehicle would get hung up on them. This is especially true for typical bollard spacing. > If there is a tree between me and a speeding car, I would much rather it be a Smart car than just about any other car. I think you’re overestimating the difference it would make. Like I said above, the smaller area of a smart car makes it less likely to actually catch the tree (by definition) and the relatively rigid frame isn’t doing much to dissipate the energy it’s carrying. Looks can be deceiving. I know everyone wants to believe smart cars are super safe alternatives, but any of these thousand pound vehicles isn’t going to be good to go up against. The differences are more nuanced than your eyes would tell you.

dghlsakjg 3y ago
Do you have any sources or reading about this? I would love to see something more than conjecture about a VERY unintuitive idea. Newton was pretty adamant that an object weighing 5k lbs (an F-150) would impart quite a bit more force than an object weighing 2k pounds (an economy car). If all of the force is being imparted into a planter, a tree, or the front of a 7-eleven, I'm still inclined to believe that more force, higher off the ground, is going to matter a whole lot more than a few extra square feet. One way or another the energy is going somewhere, and there is A LOT more energy in a pickup truck. Also, keep in mind, the crumple zone protects the passenger compartment, not the object being hit. The bumper of an f150 is right in front of a ladder frame to which several thousand pounds of iron machinery is bolted. I'll still take the smaller, faster stopping, more maneuverable, less energetic battering ram.