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.
Interstate 90, Chicago, IL. The Chicago Skyway is a 7.8 mile toll bridge connecting downtown Chicago with East Chicago, IN. For the longest time, since the bridge was opened in 1958, it was considered to be part of I-90 â the longest Interstate highway in the United States. In 1999, however, the city of Chicago discovered in looking through its old records that it was never technically approved as an Interstate highway.