Let's talk roads...
Frankly, their implementation is unsatisfying, and is 'illogical'. They 'magically' appear when a tech is researched, and their route is often random and unhelpful.
Fix: first, when the road tech is researched roads don't magically appear. Instead, the 'engineer' skill is made available (alternative -- engineer unit is available). The road building mechanic is/was already in game, so this doesn't need to be made from scratch.
Option1: Only use the first road building tech (roads between cities), drop the second one (economics? -- the one that creates roads to outposts). This is the simplest option, and allows roads built to anywhere.
Option2: The first road building tech allows roads only between cities. This would require 'pre-routing' a road -- perhaps by holding SHFT and selecting tiles starting from a city and ending at a second city (and requires a starting/ending city tile check). The route would then be set and the road constructed 'by hand' on said route. The second road building tech would then remove the 'pre-routing' requirement, and allow building roads to/from anywhere 'by hand'. Option2 requires more work, and while it's more in keeping with the current design the extra effort required is not likely worth it.
Benefits of either option:
-We can select routes, so no more routing through an occupied dragon lair, or enemy sov territory, or a new city connecting to a distant random city instead of a more centrally located city, or a city only connecting to one city, etc.
-no more magically appearing roads
-we can build roads towards other sovs or towards to-be-settled territory
Problems:
-this allows roads to anywhere, and better route selection, so would greatly increase movement. Partial fix is to reduce road movement bonus to 2x instead of current 4x.
-players are better able to take advantage of roading to anywhere, putting AI at even greater disadvantage. Fixing this (by improving AI which is th e Holy Grail) would be hard, perhaps not possible given time/resources. Partial fix is to give AI sovs magically appearing roads as currently implemented (though I'd allow roads between a city and its 2 closest cities, not just 1 city as currently implemented). Yes this is 'cheating' but we'd be gaining a whole lot (better road placement though slower to appear, while not giving up much to AI sovs).