cars: what is the controlled variable of our perception

Can someone create the following program:

Draw “cars” moving at a velocity, v:

v

O —>

There is a distance,d, between the cars:

d

O>-------|O

The velocity depends on this distance:

v = f(d)

A thought experiment: Is the controlled variable velocity or distance?

Hypothesis: The dependent variable is the “speed limit”.

Note: We do not define a “goal-speed”.

[Martin Taylor 2016.11.19.16.55]

Can someone create the following program:

Draw "cars" moving at a velocity, v:

v
O --->

There is a distance,d, between the cars:

d
O>-------|O

The velocity depends on this distance:

v = f(d)

A thought experiment: Is the controlled variable velocity or distance?

Hypothesis: The dependent variable is the "speed limit".

Note: We do not define a "goal-speed".

What do you mean by "the dependent variable"? And how would it apply on sections of the German autobahn on which there is no speed limit?

An anecdote: One day I was cruising comfortably in the slow lane on a lightly travelled portion of the autobahn between Nuremberg and Munich at 170 kph (about 105 mph, which I find to be about the easiest speed for casual driving on the autobahn), when I was passed in the middle lane by someone who just whooshed by at, I guessed, 240 kph. At the same moment, that car was being zipped past by a car that I figured must have been going about 300 kph. It all felt quite natural and safe. But at that moment none of us had our speed influenced by any car ahead of us.

Moving from the direct question to driving experience, my subjective impression is that I control my perception of the time to reach the point where the car in front is now, with a reference vale that depends on the speed (on the expressway about 2 seconds at a guess), and that time and speed determine the reference distance, which is what I actually control. At least I subjectively feel this to be the case on an expressway when there does not seem to be anyone cutting in, changing lanes in front of me. I don't know what that has to do with what I unconsciously control and control for.

Martin