Sisyphus was a character of Greek mythology who, for his misdeeds, was condemned to roll a stone up a hill, only to see it roll back down and start over again. The legend offers several analogies to introduce key concepts behind transportation, which are volume, distance, friction, and effort.
- Volume represents a number of passengers or freight that can be carried as a single load.
- Friction is the difficulty of moving a volume per unit of distance, often referred to as the friction of distance. For instance, it can be related to the quality of transport infrastructure.
- Effort is the amount of energy required to move a volume per unit of distance, considering the friction. It is commonly represented as the cost of transport. Essentially, Effort = f(volume, distance, friction).
If friction was reduced, it would require less effort to move the same volume over a distance. A core goal of transportation is consequently to reduce the friction of distance, mostly through infrastructure, capacity, and technological improvements.
Another element of the myth is its repetitiveness, which applies to transportation as well. Commuting is an activity that must constantly be repeated as the effort spent on one commute cannot be transferred to another. The same applies to supply goods to the market, which is a process that needs to be repeated continuously.