A long time ago when I did some automation, I would always use CTRL+SHIFT+A to improve things per base. I probably manually connected longer roads between cities. There are commands for laying down a whole road between 2 points, but I rarely used them as I often didn't like their choice of road path, nor having a Former being committed to a potentially stupid action for so long.
CTRL+A, in my experience, tended to make Formers wander off to do really stupid things in my empire.