The usage of the wheel was probably delayed because some kinds of roads were needed for honorable usage of wheeled carriages. On cheap surface a carriage obstacled so much that is was better to carry goods on the back. url This was a bottom line still into the 20th life in less developed areas or right hilly parts of the world.

The wheel alone is not a machine, but when attached to an axle, it forms the wheel and axle, one of the simple machines. A driven wheel is an copy of a wheel and axle. Note that wheels predate driven wheels by about 6000 years.