Generally travel on secondary roads will take longer because (1) Speed limits are lower, and (2) secondary roads go through towns and villages that are likely to have lower speed limits and stop lights and stop signs. That said, I enjoy driving the secondary roads because they are much more scenic and I often find interesting shops and unique restaurants in small towns.
secondary roads
10mins
No. There are roads that will take you around the US but there is not one single road that will take you around the US.
They built straight roads so that they could travel quicker; thus covering less territory.
longer than it take a man
Given there are 57 million miles of roads, it would take 1140000 hours, 47500 days, or about 130 years.
Forever. There are no roads from the mainland to any of the Caribbean islands.
That depends on where you start from. It will take a lot longer to travel from California than it will to travel from Georgia.
longer than it take a man
That is about 220 miles using I-40. It is longer if you take older roads.
It might take a while depending on the traffic, but there are plenty of good roads to get around on...
Soil nutrients remain in the area which enables plants to grow.