Dirt roads allow Settlers to move faster, thus to be more efficient.
Remove Road orders builders to destroy all roads in a given area. Roads to be removed are marked with a red cross.
Settlers walking speed can be reduced or increased in many different ways, for example the more confident they are the faster they will move but if they are sick they will move slower.
Settlers will always look for the shortest route to travel from one point to another, however if a road allows to travel faster they will favor the longer way.