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 thoroughfare used primarily for movement of traffic. Roads differ from streets, whose primary use is local access. They also differ from stroads, which combine the features of streets and roads. Most modern roads are paved. Th ...

, bus,

streetcar A tram (also known as a streetcar or trolley in Canada and the United States) is an urban rail transit in which vehicles, whether individual railcars or multiple-unit trains, run on tramway tracks on urban public streets; some include s ...

, or

light rail Light rail (or light rail transit, abbreviated to LRT) is a form of passenger urban rail transit that uses rolling stock derived from tram technology National Conference of the Transportation Research Board while also having some features from ...

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. The one-way streets may be separated by just a single block, such as in a grid network, 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 Commerce, commercial and business center 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 wit ...

. 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

The

Sydney central business district The Sydney central business district (CBD) is the historical and main Central business district, commercial centre of Sydney. The CBD is Sydney's city centre, or Sydney City, and the two terms are used interchangeably. Colloquially, the CBD or ...

features a number of one way pairs. One example is Pitt Street with

Castlereagh Street Castlereagh Street is a major street located in the Sydney central business district in New South Wales, Australia. The street runs north-to-south, in a One-way traffic, one way direction only. Description Castlereagh Street's northern terminu ...

. Pitt street carries only northbound traffic from Goulburn Street to Market Street. Castlreagh Street only carries southbound traffic on its entire length from Hunter Street to Hay Street.

Trams A tram (also known as a streetcar or trolley in Canada and the United States) is an urban rail transit in which Rolling stock, vehicles, whether individual railcars or multiple-unit trains, run on tramway tracks on urban public streets; some ...

once ran from

Central station Central stations or central railway stations emerged in the second half of the nineteenth century as railway stations that had initially been built on the edge of city centres were enveloped by urban expansion and became an integral part of the ...

Circular Quay Circular Quay is a harbour, former working port and now international passenger shipping terminal, public piazza and tourism precinct, heritage area, and transport node located in Sydney, New South Wales, Australia, on the northern edge of the ...

along Pitt Street and back to Central station along Castlereigh, Bligh, Bent and Loftus Streets. Other examples are

York York is a cathedral city in North Yorkshire, England, with Roman Britain, Roman origins, sited at the confluence of the rivers River Ouse, Yorkshire, Ouse and River Foss, Foss. It has many historic buildings and other structures, such as a Yor ...

and Clarence Streets between the Harbour Bridge and

Town Hall In local government, a city hall, town hall, civic centre (in the UK or Australia), guildhall, or municipal hall (in the Philippines) is the chief administrative building of a city, town, or other municipality. It usually houses the city o ...

, and

King King is a royal title given to a male monarch. A king is an Absolute monarchy, absolute monarch if he holds unrestricted Government, governmental power or exercises full sovereignty over a nation. Conversely, he is a Constitutional monarchy, ...

and Market Streets between

Sussex Sussex (Help:IPA/English, /ˈsʌsɪks/; from the Old English ''Sūþseaxe''; lit. 'South Saxons'; 'Sussex') is an area within South East England that was historically a kingdom of Sussex, kingdom and, later, a Historic counties of England, ...

and Elizabeth Streets. In Redfern, Elizabeth Street is paired with Chalmers Street between Redfern Street and Eddy Avenue. Prior to the opening of the Eastern Distributor in 1999, Bourke and Crown Streets were paired between Woolloomooloo and Waterloo after which they were converted back to two-way streets. In the Brisbane central business district, Ann Street is paired with Turbot Street and George Street with North Quay, the latter by the Brisbane River. In Southbank, Merivale Street is paired with Cordelia Street from Montague Road to Vulture Street. In East Brisbane, Vulture Street is paired with Stanley Street. In the Hobart central business district a couplet of Davey Street and Macquarie Street traverse the length of the city centre. The Tasman Highway joins the pair at the northeastern end at an interchange with the Brooker Highway. This current alignment was implemented in 1987 to coincide with the completion of the Sheraton Hotel. It was originally intended that the couplet system would serve as a stop gap measure prior to the construction of a freeway in Hobart's Transportation study of 1965. Prior to this, all traffic in Hobart was two-way.

Canada

Alberta Highway 2 is a one-way pair in southern

Edmonton Edmonton is the capital city of the Provinces and territories of Canada, Canadian province of Alberta. It is situated on the North Saskatchewan River and is the centre of the Edmonton Metropolitan Region, which is surrounded by Central Alberta ...

on Calgary Trail and Gateway Boulevard between 31 Avenue NW and Whitemud Drive. Alberta Highway 2 is also one-way pair through the towns of Fort Macleod (23 and 25 Streets; cosigned with

Alberta Highway 3 Highway 3 (officially named the Crowsnest Highway) is a List of Alberta provincial highways, highway that traverses southern Alberta, Canada, running from the Crowsnest Pass through Lethbridge to the Trans-Canada Highway in Medicine Hat. Tog ...

) and Nanton (20 and 21 Avenues).

Alberta Highway 16 Alberta Provincial Highway No. 16, commonly referred to as Highway 16, is a major east–west highway in central Alberta, Canada, connecting Jasper, Alberta, Jasper to Lloydminster via Edmonton. It forms a portion of the Yellowhead Highway, ...

( Yellowhead Highway) is a one-way pair through the town of Edson (2nd & 4th Avenues).

British Columbia Highway 99 Highway 99 is a provincial highway in British Columbia that runs from the U.S. border to near Cache Creek, serving Greater Vancouver and the Squamish–Lillooet corridor. It is a major north–south artery within Vancouver and connects the c ...

is a one-way pair in downtown

Vancouver Vancouver is a major city in Western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the cit ...

on Seymour and Howe Streets between the Granville Street Bridge and Georgia Street.

British Columbia Highway 97 Highway 97 is a major highway in the Canadian province of British Columbia. It is the longest continuously numbered route in the province, running and is the only route that runs the entire north–south length of British Columbia, connecting ...

is a one-way pair through the community of Westbank in West Kelowna, following Main Street and Dobbin Road.

Saskatchewan Highway 1 Highway 1 is the Saskatchewan section of the Trans-Canada Highway mainland route. The total distance of the Trans-Canada Highway in Saskatchewan is . The highway traverses Saskatchewan from the western border with Alberta, from Alberta Highwa ...

(

Trans-Canada Highway The Trans-Canada Highway (Canadian French, French: ; abbreviated as the TCH or T-Can) is a transcontinental federal–provincial highway system that travels through all ten provinces of Canada, from the Pacific Ocean on the west coast to the A ...

) splits into a functional one-way pair for between Uren and Ernfold, with the entire village of Ernfold being located between the eastbound and westbound lanes.

Japan

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

Aomori Prefecture is a Prefectures of Japan, prefecture of Japan in the Tōhoku region. The prefecture's capital, largest city, and namesake is the city of Aomori (city), Aomori. Aomori is the northernmost prefecture on Japan's main island, Honshu, and is border ...

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

Jersey City, New Jersey Jersey City is the List of municipalities in New Jersey, second-most populous

, between the end of the New Jersey Turnpike Newark Bay Extension and the Holland Tunnel, which leads into

New York City New York, often called New York City (NYC), is the most populous city in the United States, located at the southern tip of New York State on one of the world's largest natural harbors. The city comprises five boroughs, each coextensive w ...

, New York. 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 thoroughfare in the borough (New York City), borough of Manhattan in New York City. The avenue runs south from 143rd Street (Manhattan), West 143rd Street in Harlem to Washington Square Park in Greenwich Village. The se ...

with

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

. Others include First Avenue with Second Avenue; Third Avenue with

Lexington Avenue Lexington Avenue, often colloquially abbreviated as "Lex", is an avenue on the East Side (Manhattan), East Side of Manhattan in New York City. The avenue carries southbound one-way traffic from East 131st Street (Manhattan), 131st Street to Gra ...

; and Seventh Avenue with either

Sixth Avenue Sixth Avenue, also known as Avenue of the Americas, is a major thoroughfare in the New York City borough of Manhattan. The avenue is commercial for much of its length, and traffic runs northbound, or uptown. Sixth Avenue begins four blocks b ...

or Eighth Avenue. Two major streets in the city of

Pittsburgh Pittsburgh ( ) is a city in Allegheny County, Pennsylvania, United States, and its county seat. It is the List of municipalities in Pennsylvania#Municipalities, second-most populous city in Pennsylvania (after Philadelphia) and the List of Un ...

serve as a one-way pair; Forbes Avenue and

. Both streets begin in

Downtown ''Downtown'' is a term primarily used in American and Canadian English 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 district ( ...

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

Market Square A market square (also known as a market place) is an urban square meant for trading, in which a market is held. It is an important feature of many towns and cities around the world. A market square is an open area where market stalls are tradit ...

, with Forbes serving outbound traffic and Fifth serving inbound traffic, going through Uptown and

Oakland Oakland is a city in the East Bay region of the San Francisco Bay Area in the U.S. state of California. It is the county seat and most populous city in Alameda County, with a population of 440,646 in 2020. A major West Coast port, Oakland is ...

before both streets end up with two-way traffic and diverge, with Fifth Avenue eventually terminating in Highland Park, while Forbes terminates in Wilkinsburg just outside the city limits. The mostly two-way Boulevard of the Allies 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 the List of cities in Oregon, most populous city in the U.S. state of Oregon, located in the Pacific Northwest region. Situated close to northwest Oregon at the confluence of the Willamette River, Willamette and Columbia River, ...

, 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 United States, transportation in the rest of the United States, the primary mode of local transportation in Portland, Oregon is the automobile. Metro (Oregon regional government), Metro, the metropolitan area's regional ...

, for more details. By contrast, the Portland Transit Mall, 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) is the central business district of the city of Los Angeles. It is part of the Central Los Angeles region and covers a area. As of 2020, it contains over 500,000 jobs and has a population of roughly 85,000 residents ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

. These include 3rd and 4th Streets, 5th and 6th Streets, 8th and 9th Streets, 11th and 12th Streets, and Main and Spring Streets. Levick Street and Robbins Street in

Philadelphia Philadelphia ( ), colloquially referred to as Philly, is the List of municipalities in Pennsylvania, most populous city in the U.S. state of Pennsylvania and the List of United States cities by population, sixth-most populous city in the Unit ...

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

Mayfair Mayfair is an area of Westminster, London, England, in the City of Westminster. It is in Central London and part of the West End. It is between Oxford Street, Regent Street, Piccadilly and Park Lane and one of the most expensive districts ...

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

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

, Princeton Street carries 4 miles of SR-438 near

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

. 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

{{Reflist Types of roads