Bypass (road)

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A bypass is a road or highway that avoids or "bypasses" a built-up area, town, or village, to let through traffic flow without interference from local traffic, to reduce congestion in the built-up area, and to improve road safety.

In the Interstate highway system in the USA, bypasses and loops are designated with a three digit number beginning with an even digit.

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.

The idea of bypasses predates the use of cars. The first (northern) London bypass, between Paddington and Islington (now Marylebone Road), was started in 1756.

The book The Hitchhiker's Guide to the Galaxy mentions bypasses. It says "Bypasses are devices which allow some people to drive from point A to point B very fast whilst 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 of point B are so keen to get there, and what's so great about point B that so many people of 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."

In the USA, bypass routes are a type of bannered highway used 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" bannered routes remain where the mainline of the highway is prohibited for trucks.

In a few cases, both a bypass and a business route exist, sometimes without a non-bannered highway (this is the case in Lexington, Kentucky with U.S. Highway 60). Bypass routes are less common than business routes.

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. Examples of these include Interstate highway beltways and U.S. Highways constructed to circumvent downtown areas (e.g., US 60 bypassing Williamsburg, Virginia and Interstate 75 bypassing Tampa and St. Petersburg, Florida). These bypasses are not always bannered.

Bypass (road)

See also