Quote:
   | Originally Posted by Carbon749 thought they used the white marks on the road as a second check on speed etc. I thought they took 2 pic's and measured the change in vehicle position using the lines. That way then can also calculate your speed, knowing the distance covered in a set time between the 2 pic's being taken. | 
 
    Yep that's what i thought.  Those white lines are so handy.  
