Let's assume that 'wheel' hasn't been invented ever.
First of all, all of the transportation such as car, bicycle, subway, and motorcycle will be gone. As a result of disappearance, there would be no road and no traffic jam neither. You might be glad to imagine the World with no traffic jam, but you need to consider further situation to understand the real result.
Concept of city itself will disappear; people would live only in their radius of action as tribal society did before. It would be hard to come and go between Seoul and Pusan as hard between South Korea and USA is. Also both of overland transport and shipping will be impossible without wheel, life of people will be self-sufficient, and after all, people will return to a primitive agrarian society.
As we looked into assumption, wheel is necessary to maintain our society, because of invention of wheel; society could be developed to this extent.
