The Romans were the greatest road builders of the Ancient World. Built to move the Army and transport goods at rates of more than twenty mile per day, roads tied the Empire together.
Building the base of the road was a fine science that included a strong foundation with proper drainage. The roads were so well constructed that many are sections are still in use today.
The standard road was 1 meter thick and 2.4 meters wide(up to 5 meters on turns and other special situations). and as straight as possible.
Up to 50,000 miles of paved road crisscrossed the Empire. It was not until the mid 20th century that any country on Earth passed this amount (the US with the construction of the interstate highway and street paving for automobiles).