A one-way pair, one-way couple, or couplet refers to that portion of a bi-directional traffic facilitysuch as a

road A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation. There are many types of ...

, bus, streetcar, or light rail linewhere its opposing flows exist as two independent and roughly parallel facilities.

Description

In the context of roads, a one-way pair consists of two one-way streets whose flows combine on one or both ends into a single

two-way street A two-way street is a street that allows vehicles to travel in both directions. On most two-way streets, especially main streets, a line is painted down the middle of the road to remind drivers to stay on their side of the road. Sometimes one por ...

. The one-way streets may be separated by just a single block, such as in a

grid network Elex Media Komputindo is a publishing company in Indonesia which publishes books, comics, magazines, novels and other print media. Established on January 15, 1985, Elex Media Komputindo is a subsidiary of Kompas Gramedia Group. Elex is headquarte ...

, or may be spaced further apart with intermediate parallel roads. One use of a one-way pair is to increase the vehicular capacity of a major route through a developed area such as a

central business district A central business district (CBD) is the commercial and business centre of a city. It contains commercial space and offices, and in larger cities will often be described as a financial district. Geographically, it often coincides with the "city ...

. If not carefully treated with other traffic calming features, the benefit in vehicular capacity is offset by a potential for increased road user deaths, in particular people walking and biking. A one-way pair can be created by converting segments of two-way streets into one-way streets, which allows lanes to be added without widening. On occasion, "couplet" has been applied specifically to the point where the one-way streets and the two-way street meet, rather than the paired one-way streets themselves. Flows on a one-way pair may follow the traffic handedness convention of the locale, or may be switched. Following the convention allows a one-way pair to be more easily integrated into an existing network of two-way streets, as a single two-way street is effectively split into the two sides of the pair, as in the diagram below:

Examples

Australia

Sydney CBD features a number of one way pairs, all north-south. One example is Pitt Street with Castlereagh Street. Pitt street carries only northbound traffic from Goulbern Street to Market Street. Castlreagh Street only carries southbound traffic on its entire length from Hunter Street to Hay Street near central station. Trams once ran from Central Station to Circular Quay along Pitt Street and back to Central Station along Castlereigh, Bligh, Bent and Loftus Streets. In Redfern, part of Elizabeth Street is paired with Chalmers street. This follows the usual flow convention. In the Brisbane CBD Ann Street is paired with

Turbot Street Turbot Street runs parallel to Ann Street and is on the northern side of the Brisbane central business district, Brisbane CBD in Queensland, Australia. It is a major thoroughfare, linking as a three-to-five lane one-way street with the Riversid ...

and George Street with North Quay, the latter by the

Brisbane River The Brisbane River is the longest river in South East Queensland, Australia, and flows through the city of Brisbane, before emptying into Moreton Bay on the Coral Sea. John Oxley, the first European to explore the river, named it after the Go ...

. In Southbank, Merivale Street is paired with Cordelia Street from Montague Road to Vulture Street. In

East Brisbane East Brisbane is an inner southern suburb of the City of Brisbane, Queensland, Australia. In the , East Brisbane had a population of 5,934 people. Geography East Brisbane is located south-east of the CBD. It is mostly residential, with some s ...

, Vulture Street is paired with

Stanley Street Stanley Street may refer to: Streets: *Stanley Street, Brisbane *Stanley Street, East Sydney *Stanley Street, Hong Kong *Stanley Street, Liverpool * Stanley Street (Montreal) * Stanley Street, Singapore In fiction: *Stanley Street, the prime setti ...

Japan

Japan National Route 340 travels through the central part of Hachinohe in

Aomori Prefecture is a prefecture of Japan in the Tōhoku region. The prefecture's capital, largest city, and namesake is the city of Aomori. Aomori is the northernmost prefecture on Japan's main island, Honshu, and is bordered by the Pacific Ocean to the east, ...

as a one-way pair between its northern terminus at an intersection with Japan National Route 45 and Aomori Prefecture Route 251.

United States

Interstate 78 Interstate 78 (I-78) is an east–west Interstate Highway in the Northeastern United States, running from I-81 northeast of Harrisburg, Pennsylvania, through Allentown to western and northern New Jersey and terminating at the Holland Tunn ...

travels along a one-way pair of surface streets, 12th Street and 14th Street, in

Jersey City, New Jersey Jersey City is the second-most populous city in the U.S. state of New Jersey, after Newark.New Jersey Turnpike The New Jersey Turnpike (NJTP) is a system of controlled-access highways in the U.S. state of New Jersey. The turnpike is maintained by the New Jersey Turnpike Authority (NJTA).The Garden State Parkway, although maintained by NJTA, is not consi ...

Newark Bay Extension and the Holland Tunnel, which leads into

New York City New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...

New York New York most commonly refers to: * New York City, the most populous city in the United States, located in the state of New York * New York (state), a state in the northeastern United States New York may also refer to: Film and television * '' ...

. There are hundreds of one-way pairs among the streets and avenues of New York City. One example is

Fifth Avenue Fifth Avenue is a major and prominent thoroughfare in the borough of Manhattan in New York City. It stretches north from Washington Square Park in Greenwich Village to West 143rd Street in Harlem. It is one of the most expensive shopping stre ...

with

Madison Avenue Madison Avenue is a north-south avenue in the borough of Manhattan in New York City, United States, that carries northbound one-way traffic. It runs from Madison Square (at 23rd Street) to meet the southbound Harlem River Drive at 142nd Stre ...

. Others include First Avenue with Second Avenue;

Third Avenue Third Avenue is a north-south thoroughfare on the East Side of the New York City borough of Manhattan, as well as in the center portion of the Bronx. Its southern end is at Astor Place and St. Mark's Place. It transitions into Cooper Square ...

with

Lexington Avenue Lexington Avenue, often colloquially abbreviated as "Lex", is an avenue on the East Side of the borough of Manhattan in New York City that carries southbound one-way traffic from East 131st Street to Gramercy Park at East 21st Street. Along it ...

; and Seventh Avenue with either

Sixth Avenue Sixth Avenue – also known as Avenue of the Americas, although this name is seldom used by New Yorkers, p.24 – is a major thoroughfare in New York City's borough of Manhattan, on which traffic runs northbound, or "uptown". It is commercial ...

or Eighth Avenue. Two major streets in the city of

Pittsburgh Pittsburgh ( ) is a city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, United States, and the county seat of Allegheny County, Pennsylvania, Allegheny County. It is the most populous city in both Allegheny County and Wester ...

serve as a one-way pair; Forbes Avenue and

. Both streets begin in

Downtown ''Downtown'' is a term primarily used in North America by English speakers to refer to a city's sometimes commercial, cultural and often the historical, political and geographic heart. It is often synonymous with its central business distric ...

near Point State Park before becoming a one-way pair just east of

Market Square The market square (or sometimes, the market place) is a Town square, square meant for trading, in which a market is held. It is an important feature of many towns and cities around the world.Uptown Uptown may refer to: Neighborhoods or regions in several cities United States * Uptown, entertainment district east of Downtown and Midtown Albuquerque, New Mexico * Uptown Charlotte, North Carolina * Uptown, area surrounding the University of C ...

and

Oakland Oakland is the largest city and the county seat of Alameda County, California, United States. A major West Coast port, Oakland is the largest city in the East Bay region of the San Francisco Bay Area, the third largest city overall in the Bay A ...

before both streets end up with two-way traffic and diverge, with Fifth Avenue eventually terminating in Highland Park, while Forbes terminates in

Wilkinsburg Wilkinsburg is a borough in Allegheny County, Pennsylvania. The borough has a population of 15,930 as of the 2010 census. Wilkinsburg is part of the Pittsburgh metropolitan area. The borough was named for John Wilkins Jr., a United States Army ...

just outside the city limits. The mostly two-way

Boulevard of the Allies The Boulevard of the Allies is a mostly four-lane road in the U.S. state of Pennsylvania, connecting Downtown Pittsburgh with the Oakland neighborhood of the city. Because of its lengthy name, locals sometimes refer to it as simply "The Boulevard ...

parallels Forbes and Fifth for most of the time the two streets are a one-way pair. The east side of

Portland, Oregon Portland (, ) is a port city in the Pacific Northwest and the largest city in the U.S. state of Oregon. Situated at the confluence of the Willamette and Columbia rivers, Portland is the county seat of Multnomah County, the most populous co ...

, features a number of one-way pairs, both north–south and east–west, with the east–west pairs being associated with bridges; these all follow the usual flow convention – see

Transportation in Portland, Oregon Like transportation in the rest of the United States, the primary mode of local transportation in Portland, Oregon is the automobile. Metro, the metropolitan area's regional government, has a regional master plan in which transit-oriented develo ...

, for more details. By contrast, the

Portland Transit Mall The Portland Transit Mall is a public transit corridor that travels north–south through the center of downtown in Portland, Oregon, United States. It comprises a pair of one-way streets—6th Avenue for northbound traffic and 5th Avenue for ...

, which is a public transportation (bus and rail) corridor, has the opposite flow, with the westernmost component (6th Avenue) running north, with the eastern component (5th Avenue) running south. There are a number of one-way pairs in

Downtown Los Angeles Downtown Los Angeles (DTLA) contains the central business district of Los Angeles. In addition, it contains a diverse residential area of some 85,000 people, and covers . A 2013 study found that the district is home to over 500,000 jobs. It is ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

. These include 3rd and 4th Streets, 5th and 6th Streets, 8th and 9th Streets, 11th and 12th Streets, and

Main Main may refer to: Geography * Main River (disambiguation) **Most commonly the Main (river) in Germany * Main, Iran, a village in Fars Province *"Spanish Main", the Caribbean coasts of mainland Spanish territories in the 16th and 17th centuries ...

and Spring Streets. Levick Street and Robbins Street in

Philadelphia Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania, the sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. Sinc ...

are considered a one-way pair. The streets carry traffic to and from the Tacony-Palmyra Bridge through the

Mayfair Mayfair is an affluent area in the West End of London towards the eastern edge of Hyde Park, in the City of Westminster, between Oxford Street, Regent Street, Piccadilly and Park Lane. It is one of the most expensive districts in the world. ...

and Wissinoming neighborhoods. Between Frankford Avenue and Roosevelt Boulevard, the streets carry US 13 in their respective direction. In Orlando,

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

, Princeton Street carries 4 miles of SR-438 near

Interstate 4 Interstate 4 (I-4) is an Interstate Highway located entirely within the U.S. state of Florida, maintained by the Florida Department of Transportation (FDOT). Spanning along a generally southwest–northeast axis, I-4 is entirely concurrent wi ...

. Over a portion of that, Smith Street carries the westbound traffic. At Lake Lawsona, Mills Avenue splits into Jackson Street northbound and Thornton Avenue southbound. In Virginia Beach, Virginia, the eastern end of Interstate 264 transitions to 21st and 22nd Street, each going in its respective direction.

References