3 ms·

Humans can detect accelerations as low as .25 mph/s so while you might not know exactly what your acceleration rate is, you definitely would be aware that you a

by jjk166 3y ago

Humans can detect accelerations as low as .25 mph/s so while you might not know exactly what your acceleration rate is, you definitely would be aware that you are accelerating and whether your efforts to compensate are increasing or decreasing it. And these very low acceleration rates take a very long time to significantly alter your speed. On an analogue dial you probably wouldn't even notice the movement. In practice, maintaining speed in a vehicle is pretty darn simple.

lmm 3y ago
> Humans can detect accelerations as low as .25 mph/s Maybe under ideal conditions. Not while driving. And below .25 is still enough to have you drift off speed. > you definitely would be aware that you are accelerating and whether your efforts to compensate are increasing or decreasing it. It is by no means definite. It's very easy to drift off the correct speed when e.g. the slope of the road changes, even if you're trying not to.
- jjk166 3y ago
  With what level of precision are you trying to maintain constant speed? At .25 mph/s it takes 4 seconds to have a 1 mph change in speed. At highway speeds the change in your position from where you'd expect to be at perfectly constant velocity would be 0.8%, or about 3 feet off. That's nothing compared to the variability of your speedometer, which is only accurate to about +/- 10%. If you're a blue angel trying to fly in close formation at hundreds of miles per hour, yeah that's not good enough, but for a normal person driving on a road it is trivially simple to keep your speed within the margin of error of your speedometer.
Turskarama 3y ago
You might be able to detect an acceleration, but I bet you can't accurate gauge how fast that acceleration is.
- jjk166 3y ago
  But why do you need to gauge rate of acceleration? If you're trying to maintain constant speed, you want an absence of acceleration.

by jjk166 3y ago

lmm 3y ago

> Humans can detect accelerations as low as .25 mph/s Maybe under ideal conditions. Not while driving. And below .25 is still enough to have you drift off speed. > you definitely would be aware that you are accelerating and whether your efforts to compensate are increasing or decreasing it. It is by no means definite. It's very easy to drift off the correct speed when e.g. the slope of the road changes, even if you're trying not to.

jjk166 3y ago
With what level of precision are you trying to maintain constant speed? At .25 mph/s it takes 4 seconds to have a 1 mph change in speed. At highway speeds the change in your position from where you'd expect to be at perfectly constant velocity would be 0.8%, or about 3 feet off. That's nothing compared to the variability of your speedometer, which is only accurate to about +/- 10%. If you're a blue angel trying to fly in close formation at hundreds of miles per hour, yeah that's not good enough, but for a normal person driving on a road it is trivially simple to keep your speed within the margin of error of your speedometer.

Turskarama 3y ago

You might be able to detect an acceleration, but I bet you can't accurate gauge how fast that acceleration is.

jjk166 3y ago
But why do you need to gauge rate of acceleration? If you're trying to maintain constant speed, you want an absence of acceleration.