Crazy road paths
Instead of a direct path between cities, I got one that looped around a mountain and was longer by several tiles. Another faction built a city on the road and severely restricted its utility.
Figured out that the criteria for the path was what a pioneer would take thus choosing tiles that do not slow down movement. A shorter path would be obtained by choosing the path that a scout would take. If I were using a pioneer to build the road I would still choose the shorter path even if it would take longer to build.
Suggest having Engineers to build roads. Have a switch to turn on road building so that all you have to do is move the Engineer. Could be used for other tasks like draining swamps, digging canals for irrigation, and building city walls.