One-way pair
Encyclopedia
A one-way pair, one-way couple, or just couplet is a pair of parallel, usually one-way streets that carry opposite directions of a signed route or major traffic
flow, or sometimes opposite directions of a bus
or streetcar route.
The usual purpose is to provide higher capacity by increasing the number of lanes in each direction. It also allows easier creation of a green wave
by adjusting traffic light
s on the through route, because fewer phases are needed at each intersection.
"One-way pair" refers specifically to a single major route, divided across two streets; more extensive is when there is a grid of multiple alternating one-way streets, which is common is city centers.
– meaning opposing traffic follows the usual left/right convention of the country, e.g., in the United States and most of the world, northbound traffic on east side, southbound traffic on west side, following the "drive on the right" convention – though occasionally flow is switched. Following this 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:
travels along a one-way pair of surface streets, 12th Street and 14th Street, in Jersey City, New Jersey
, between the end of the New Jersey Turnpike
Newark Bay Extension and the Holland Tunnel
, which leads into New York City
.
The east side of Portland, Oregon
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 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 Ave) running north, with the eastern component (5th Ave) running south.
Traffic
Traffic on roads may consist of pedestrians, ridden or herded animals, vehicles, streetcars and other conveyances, either singly or together, while using the public way for purposes of travel...
flow, or sometimes opposite directions of a bus
Bus
A bus is a road vehicle designed to carry passengers. Buses can have a capacity as high as 300 passengers. The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are...
or streetcar route.
The usual purpose is to provide higher capacity by increasing the number of lanes in each direction. It also allows easier creation of a green wave
Green wave
A green wave is an intentionally induced phenomenon in which a series of traffic lights are coordinated to allow continuous traffic flow over several intersections in one main direction....
by adjusting traffic light
Traffic light
Traffic lights, which may also be known as stoplights, traffic lamps, traffic signals, signal lights, robots or semaphore, are signalling devices positioned at road intersections, pedestrian crossings and other locations to control competing flows of traffic...
s on the through route, because fewer phases are needed at each intersection.
"One-way pair" refers specifically to a single major route, divided across two streets; more extensive is when there is a grid of multiple alternating one-way streets, which is common is city centers.
Flow
On a one-way pair, traffic usually flows the same way as on a normal divided highwayDivided Highway
Divided Highway is a compilation album by American rock band The Doobie Brothers, released in 2003. . All tracks are taken from the albums Cycles and Brotherhood .-Track listing:...
– meaning opposing traffic follows the usual left/right convention of the country, e.g., in the United States and most of the world, northbound traffic on east side, southbound traffic on west side, following the "drive on the right" convention – though occasionally flow is switched. Following this 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:
/ <-- <-- <-- \
(rejoin) / <-- <-- <-- \ (split)
| |
<-- <-- / /--> --> -->\ \ <-- <--
--> --> --> --> --> --> --> --> -->
2-way 1-way 2-way
Examples
I-78Interstate 78
Interstate 78 is an Interstate Highway in the Northeast United States, running 144 miles from Interstate 81 northeast of Harrisburg, Pennsylvania, through Allentown, Pennsylvania, and western and northern New Jersey to the Holland Tunnel and Lower Manhattan in New York City.I-78 is a major road...
travels along a one-way pair of surface streets, 12th Street and 14th Street, in Jersey City, New Jersey
Jersey City, New Jersey
Jersey City is the seat of Hudson County, New Jersey, United States.Part of the New York metropolitan area, Jersey City lies between the Hudson River and Upper New York Bay across from Lower Manhattan and the Hackensack River and Newark Bay...
, between the end of the New Jersey Turnpike
New Jersey Turnpike
The New Jersey Turnpike is a toll road in New Jersey, maintained by the New Jersey Turnpike Authority. According to the International Bridge, Tunnel and Turnpike Association, the Turnpike is the nation's sixth-busiest toll road and is among one of the most heavily traveled highways in the United...
Newark Bay Extension and the Holland Tunnel
Holland Tunnel
The Holland Tunnel is a highway tunnel under the Hudson River connecting the island of Manhattan in New York City with Jersey City, New Jersey at Interstate 78 on the mainland. Unusual for an American public works project, it is not named for a government official, politician, or local hero or...
, which leads into New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
.
The east side of Portland, Oregon
Portland, Oregon
Portland is a city located in the Pacific Northwest, near the confluence of the Willamette and Columbia rivers in the U.S. state of Oregon. As of the 2010 Census, it had a population of 583,776, making it the 29th most populous city in the United States...
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 for more details. By contrast, the Portland Transit Mall
Portland Transit Mall
The Portland Transit Mall is a set of public transit corridors through the center of downtown Portland, Oregon, United States. More specifically, it is a pair of one-way streets—one for northbound traffic, the other for southbound—along which two of the three lanes are restricted to...
, which is a public transportation (bus and rail) corridor, has the opposite flow, with the westernmost component (6th Ave) running north, with the eastern component (5th Ave) running south.