- Bypass (road)
A bypass is a
roador highwaythat avoids or "bypasses" a built-up area, town, or village, to let through trafficflow without interference from local traffic, to reduce congestionin the built-up area, and to improve road safety.
If there are no strong land use controls, buildings are built along a bypass, converting it into an ordinary town road, and the bypass may eventually become as congested as the local streets it was intended to avoid. Shopping centres and some other companies often are built there for ease of access, while homes are often avoided for noise reasons.
The idea of bypasses predates the use of motor vehicles. The first (northern)
Londonbypass, the present Marylebone Roadbetween Paddingtonand Islington, was started in 1756.
Bypasses can take many years to gain planning approval and funding. Many towns and villages have been campaigning for bypasses for over 30 years e.g.
Banwellin North Somerset[http://www.bypassbanwell.co.uk/index.htm] . Bypass routes are often controversial- by definition they require the building of a road carrying heavy traffic where no road previously existed. This creates a conflict between the those who support a bypass to reduce congestion in a built up area, and those who oppose the development of (often rural) undeveloped land.
In the United States, bypass routes are a type of
auxiliary routeused on an alternative routing of a highway around a town when the main route of the highway goes through the town. The original designation of these routes were "truck routes" to divert through truck traffic away from the town, but the designation was changed to "bypass" in 1959-1960 by AASHTO. However, many "Truck" routes remain where the mainline of the highway is prohibited for trucks.
In a few cases, both a bypass and a
business routeexist, both with auxiliary signs (i.e. U.S. Highway 60in Lexington, Kentucky). Bypass routes are less common than business routes. Many of those that existed before the era of Interstate highways have lost their old designations. For example in Missouri, the old bypass route of U.S. Highway 71to the east of Kansas City, Missouriwas decertified as Interstate 435 supplanted, the remainder that existed as suburban surface route becoming Missouri State Highway 291; around St. Louis, Missouri, what had been Bypass U.S. Highway 50was absorbed into a diversion of U.S. Highway 50from Interstate 44and Interstate 64.
Interstate highwaysystem in the United States, bypasses and loops are designated with a three digit number beginning with an even digit. Note, however, that this pattern is inconsistent enough that, as in greater Des Moines, Iowathe genuine bypass is the main route (in that case, Interstate 35and Interstate 80, and the loop into downtown Des Moines is Interstate 235; or as in Omaha, Nebraska, where Interstate 680 traverses their downtown area, which is bypassed by Interstate 80 and Interstate 680.
Another meaning of the term bypass route (usually simply called a "bypass") is a highway that was constructed to bypass an area that is often congested with traffic. This includes
Interstate highway beltways and U.S. Highways constructed to circumvent downtown areas. Examples of these are U.S. Route 60bypassing Williamsburg, Virginia, U.S. Routes 31 and 20 bypassing metro South Bend, Indiana(the St. Joseph Valley Parkway), and Interstate 75bypassing Tampa and St. Petersburg, Florida. These bypasses usually carry mainline routes rather than auxiliary "bypass" routes.
The term shoofly, while common in
rail terminology, can also be applied to a short temporary roadway which bypasses a construction site or other obstruction. [cite web |url=http://www.40forward.com/global/glossary.aspx |title=Oklahoma's I-40 Crosstown Expressway: Glossary |accessdate=2008-04-16 |accessmonthday= |accessdaymonth= |accessyear= |author= |last= |first= |authorlink= |coauthors= |date= |year= |month= |format= |work= Oklahoma Department of Transportation|publisher= |pages= |language= |doi= |archiveurl= |archivedate= |quote= ] The U.S. " Manual on Uniform Traffic Control Devices" uses the term "diversion". [MUTCD [http://mutcd.fhwa.dot.gov/HTM/2003r1/part6/part6c.htm#section6C09 Section 6C.09] ]
In the more densely populated southern part of
Swedenmany bypasses have been built, both as motorways and ordinary roads. Many cities and villages however still have main roads right through them. Municipalityadministrations are often lobbying to have a bypass for safety, noise and air quality reasons. In the northern parts of Sweden fewer bypasses have been built, especially in the sparsely populated interior. Here municipality administrations are often lobbying against bypasses, since they are afraid of losing income from road travellers.
In The Hitchhiker's Guide to the Galaxy by
Douglas Adams, Arthur Dent's home is destroyed to make way for a bypass. A few minutes later, the entire Earthis destroyed by the Vogons to make way for a hyperspace bypass. In chapter 1, Adams explained what a bypass was:
Bypasses are devices that allow some people to dash from point A to point B very fast while other people dash from point B to point A very fast. People living at point C, being a point directly in between, are often given to wonder what’s so great about point A that so many people from point B are so keen to get there, and what’s so great about point B that so many people from point A are so keen to get there. They often wish that people would just once and for all work out where the hell they wanted to be.
*Israeli bypass roads
List of bannered U.S. Highways
List of Business Routes of the Interstate Highway System
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