I played arcade Night Driver at Archive.org link 

Instructions

novice, 1st gear.  I went very slowly and counted the pairs of pylons, being sure not to crash.  
66 pairs of pylons, 19 odometer turns.  
(19/66)*7=2.015 odometer turns from the bottom of the screen to the horizon.

I did it a second time.  100 pairs of pylons, 29 odometer turns.  

(29/100)*7=2.03 odometer turns from the bottom of the screen to the horizon.

I did it a third time.  99 pairs of pylons, 29 odometer turns.

(29/99)*7=2.05 odometer turns from the bottom of the screen to the horizon.  

Average of the three values: 2.032 odometer turns

This number is very good.  There are two odometer turns from the bottom of the screen to the horizon.  If our odometer has two decimal places, then it's 200 .01 increments from the bottom of the screen to the horizon.  In batari Basic, there are about 90 pixels on the y-axis.  Not sure exactly where we'll put the horizon yet.  Suppose we put the horizon at y=20, so there are 70 pixels from the bottom of the screen to the horizon.  (Note: In batari Basic, the positive y-direction is downward.  That is, y=0 is at the top of the screen and y=90 is at the bottom of the screen.)  Let's call .01 of an odometer turn a "click".  So from the bottom of the screen to the horizon, it's going to be about 70 pixels and 200 "clicks".  That's about 200/70=2.85 clicks/pixel.  To say it another way, if you're chasing down a ghost car that's on the screen in front of you, for approximately every 3 "clicks" on your odometer that you close in on the ghost car, the image of the ghost car on the screen will move 1 pixel closer to you.  I like it.  I think it's perfect.  Two decimal places for the odometers was a good choice.  For now, we'll leave it this way.