Civilization was stagnant for thousands of years. Man invented the wheel and built a cart and pulled it behind a horse. Thus the invention of transportation.
No one invented anything new for a very long time.
When the alien space ship crashed in Roswell, Nevada, the US government got all the current techonology from that ship to bring civilization to what it is today.
I am sure that we will find a way to invent some form of clean and economical transportation before we pollute the earth and run out of oil.
For now I still love to drive my VX.