Ambient noise includes all sounds present in an environ-. ment. The ambient noise level may be measured at any mo-. ment, but it will vary widely with time, e.g., with the coming. and going of trucks and aircraft. Traffic noise is higher at. noon than at midnight and higher still during the morning. and evening rush hours.
(According to the most recent U.S. numbered highway log, published in 1989 by the American Association of State Highway and Transportation Officials, the route is 3,249 miles long). In 1963, therefore, U.S. 20 became the longest road in the country. U.S. 20 is 3,365 miles long according to the 1989 log. The route begins in Boston at a junction with Massachusetts Route 2 and ends in Newport, Oregon, at a junction with U.S. 101.
Understand[edit] The north terminus of U.S. Highway 1 has always been in Fort Kent, Maine, and until 1926 the route ended in Miami, Florida. In 1938 it was extended to Key West, Florida. It is also the longest north-south highway in the United States. Although a good part of the route hugs the Atlantic coastline, much of it is quite distant from the coast. Originally, US 1 was built to provide quick travel before the Interstate system was built.