Ring road

A ring road (also known as beltline, beltway, circumferential (high)way, loop or orbital) is a road or a series of connected roads encircling a town, city, or country. The most common purpose of a ring road is to assist in reducing traffic volumes in the urban centre, such as by offering an alternate route around the city for drivers who do not need to stop in the city core. The name 'ring road' is used for the majority of metropolitan circumferential routes in the European Union, such as the Berliner Ring, the Brussels Ring, the Amsterdam Ring, the Boulevard Périphérique around Paris and the Leeds Inner and Outer ring roads. Australia, Pakistan and India also use the term ring road, as in Melbourne's Western Ring Road, Lahore's Lahore Ring Road and Hyderabad's Outer Ring Road. In Canada the term is the most commonly used, with 'orbital' also used, but to a much lesser extent. In Europe, some ring roads, particularly those of motorway standard which are longer in length, are often known as 'orbital motorways'. Examples include the London Orbital (188 km) and Rome Orbital (68 km). In the United States, many ring roads are called beltlines, beltways, or loops, such as the Capital Beltway around Washington, D.C. Some ring roads, such as Washington's Capital Beltway, use 'Inner Loop' and 'Outer Loop' terminology for directions of travel, since cardinal (compass) directions cannot be signed uniformly around the entire loop. The term 'ring road' is occasionally – and inaccurately – used interchangeably with the term 'bypass'. Bypasses around many large and small towns were built in many areas when many old roads were upgraded to four-lane status in the 1930s to 1950s, such as those along the Old National Road (now generally U.S. 40 or Interstate 70) in the United States, leaving the old road in place to serve the town or city, but allowing through travelers to continue on a wider, faster, and safer route. Construction of fully circumferential ring roads has generally occurred more recently, beginning in the 1960s in many areas, when the U.S. Interstate Highway System and similar-quality roads elsewhere were designed. Ring roads have now been built around numerous cities and metropolitan areas, including cities with multiple ring roads, irregularly shaped ring roads, and ring roads made up of various other long-distance roads. London has three ringroads (the London Orbital, the North and South Circular routes, and the Inner Ring Road). Other British cities have two (Birmingham, Leeds, Sheffield, Norwich and Glasgow). Columbus, Ohio, in the United States, also has two, while Houston, Texas will have three official ring roads (not including the downtown freeway loop). Some cities have far more – Beijing, for example, has six ring roads, simply numbered in increasing order from the city center (though skipping #1). Geographical constraints can complicate or prohibit the construction of a complete ring road. For example, the Baltimore Beltway in Maryland crosses Baltimore Harbor on a high arch bridge, and much of the partially completed Stockholm Ring Road in Sweden runs through tunnels or over long bridges. However, some towns or cities on seacoasts or near rugged mountains cannot have a full ring road, such as Dublin's ring road; or, in the US, Interstate 287, mostly in New Jersey (bypassing New York City), or Interstate 495 around Boston, none of which completely circles these seaport cities.