How were roads built & maintained throughout history?

Oct 2017
America 🇺🇸
How often were urban centers like cities, towns & villages & castles paved? Btw are castles & forts considered a type of urban center?

What about for colonial & modern history?
Oct 2009
San Diego
It should also be noted that Hitler built the modern autobahn in Germany- at a time when the surrounding nations still relied principally on dirt roads- Once the Allies got into Germany, Eisenhower was amazed by the roads and determined that Germany's road system was a Large factor in its war fighting ability and how One relatively small nation managed to so effectively wage was on that scale. As president, he pushed hard for the Interstate Highway Project which he sold to congress on the argument that it was Critical to national defense in a modern era.

The Romans essentially ruled their world because of their roads- because Rome could Move massive and well equipped armies- Rain or Shine- while their enemies were bogged down in mud. And because those same roads effectively tripled their GDP thru efficient and reliable transportation of materials and goods. And one of the most important elements of having an effective standing army is the economic wealth to afford that army.