Short answers, pulled from the story.
A road is a thoroughfare from one place to another, primarily used for the movement of traffic, while a street's primary use is local access. The two words are commonly treated as interchangeable, but the distinction matters in urban design. A stroad combines the features of both a street and a road.
The world's oldest known paved road was constructed in Egypt some time between 2600 and 2200 BC. The Sweet Track, a timber causeway in England built in the winter of 3807 BC or spring of 3806 BC, is one of the oldest engineered roads, though a 6,000-year-old trackway found in Plumstead, London, in 2009 is older still.
The AASHO Road Test of the late 1950s found that the effective damage to a road is roughly proportional to the fourth power of axle weight. A typical 80,000-pound tractor-trailer is expected to do about 7,800 times more damage than a passenger vehicle carrying 2,000 pounds on each axle.
The United States has the largest road network of any country, with 4,050,717 miles as of 2009. India has the second-largest with 4,689,842 kilometers as of 2013, followed by China with 3,583,715 kilometers as of 2007 and Brazil with 1,751,868 kilometers as of 2002.
From about 312 BC the Roman Empire built straight stone roads across Europe and North Africa, covering 78,000 kilometers through 29 major roads at its peak. In 500 BC, Darius the Great built an extensive road system for the Achaemenid Empire, including the Royal Road connecting Sardis to Susa.
In parts of the United Kingdom the standard design life is 40 years for new bitumen and concrete pavement, with maintenance planned at 10, 20, and 30-year milestones. Some asphalt is built as perpetual pavement expected to exceed 50 years, and Chicago's Wacker Drive is being rebuilt for a 100-year service life.