Answer: the ability to travel between towns.
Step-by-step explanation:
Colonial settlements produced enough goods or products that were bartered with another settlement. It was extraordinary to get the goods they needed and to give the goods they produced. However, something that was needed to make that bartering successful is the ability to trabel from one settlement to the other. The distances and the weight of the goods were two of the factors that make bartering impossible if means of transport (of that time) and roads were not available.